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Voltage drops when cranking...
#1
C
CraigH
C
CraigH
Hi all, first post as such (apart from my intro) so please bear with me.
I've got abit of knowledge of mowers and engines in general, but this new (to me) mower has me stumped and I don't want to spend anything til I narrow the problem down, this is where I'm hoping someone on here has had a similar problem....
The mower is a John Deere L105 automatic (Briggs and Stratton 14.5 hp intek single cylinder)
I got it given to me with suspected head gasket or rings gone, and it's was over filled with oil aswell.
Since I got it, it's never wanted to turn over properly so I've done a few basic maintenance bits and still no joy....
I've set the armature gap, replaced head gasket, reset tappet clearances (with piston 1/4" down), moved throttle cable as it was set so only ever revved flat out, changed oil, cleaned carb and air filter out, rebuilt starter (mainly to check and see if anything looked amiss).
The problem is still the same though, when I turn the key, the engine turns over about 1/4-1/2 of a revolution then stops dead and the starter starts to buzz....
So I've done some checking/testing and the battery is fine, I've tried another known good battery off my other mower, tried jumping it from my van, cleaned all electrical connections and earth points (I think), all of the above result in the same outcome though.
If I check the voltage (at battery, starter and solenoid) when I turn the key then it drops to 6v.....
So the big question, which is probably blindingly obvious but I can't see it, what do people think could be the problem and where should I start looking next ?
New starter motor maybe?
I've got abit of knowledge of mowers and engines in general, but this new (to me) mower has me stumped and I don't want to spend anything til I narrow the problem down, this is where I'm hoping someone on here has had a similar problem....
The mower is a John Deere L105 automatic (Briggs and Stratton 14.5 hp intek single cylinder)
I got it given to me with suspected head gasket or rings gone, and it's was over filled with oil aswell.
Since I got it, it's never wanted to turn over properly so I've done a few basic maintenance bits and still no joy....
I've set the armature gap, replaced head gasket, reset tappet clearances (with piston 1/4" down), moved throttle cable as it was set so only ever revved flat out, changed oil, cleaned carb and air filter out, rebuilt starter (mainly to check and see if anything looked amiss).
The problem is still the same though, when I turn the key, the engine turns over about 1/4-1/2 of a revolution then stops dead and the starter starts to buzz....
So I've done some checking/testing and the battery is fine, I've tried another known good battery off my other mower, tried jumping it from my van, cleaned all electrical connections and earth points (I think), all of the above result in the same outcome though.
If I check the voltage (at battery, starter and solenoid) when I turn the key then it drops to 6v.....
So the big question, which is probably blindingly obvious but I can't see it, what do people think could be the problem and where should I start looking next ?
New starter motor maybe?
#2
I
ILENGINE
I
ILENGINE
Compression release mechanism on the camshaft is broken and laying in the engine oil sump. Need to replace the camshaft
#3
C
CraigH
C
CraigH
Thanks for the advice, I'm guessing its a common thing then? Parts don't seem hard to come by and cheap enough.
Is there anything else worth doing while I've got the engine out and all apart? Was thinking of doing rings and obviously gasket set at the same time.
Any pointers for things to look out for or problems I may encounter?
Is there anything else worth doing while I've got the engine out and all apart? Was thinking of doing rings and obviously gasket set at the same time.
Any pointers for things to look out for or problems I may encounter?
#4
sgkent
sgkent
pull the sparkplug and see what it does. Measure the voltages again. If it spins and the voltage looks normal at the battery then the last post is the answer most likely. If it spins but the voltage drops way down then that battery is done for too. Just because a battery works doesn't mean it isn't 90% gone. The other engine can be easier to turn over.
#5
C
CraigH
C
CraigH
Thanks for the reply. Very good point about the other engine/battery, it's only a 10hp, but that battery was bought brand new for that mower 5 months ago so would assume it's pretty decent still after that little time.
Currently got the 'not cranking so well' battery on a slow charge so will leave it to do it's thing overnight and try it with the plug out tomorrow and see what happens.
I'll report back when I find some more results tomorrow.
Currently got the 'not cranking so well' battery on a slow charge so will leave it to do it's thing overnight and try it with the plug out tomorrow and see what happens.
I'll report back when I find some more results tomorrow.
#6
R
RayMcD
R
RayMcD
If you have lights pull them on an see if you voltage drops? Or get a clamp on light and do the test. Sounds like you just got a bad battery, load does not make this happen, something would be smoking. If the voltage is dropping you got Zero AMPS to use.. rHi all, first post as such (apart from my intro) so please bear with me.
I've got abit of knowledge of mowers and engines in general, but this new (to me) mower has me stumped and I don't want to spend anything til I narrow the problem down, this is where I'm hoping someone on here has had a similar problem....
The mower is a John Deere L105 automatic (Briggs and Stratton 14.5 hp intek single cylinder)
I got it given to me with suspected head gasket or rings gone, and it's was over filled with oil aswell.
Since I got it, it's never wanted to turn over properly so I've done a few basic maintenance bits and still no joy....
I've set the armature gap, replaced head gasket, reset tappet clearances (with piston 1/4" down), moved throttle cable as it was set so only ever revved flat out, changed oil, cleaned carb and air filter out, rebuilt starter (mainly to check and see if anything looked amiss).
The problem is still the same though, when I turn the key, the engine turns over about 1/4-1/2 of a revolution then stops dead and the starter starts to buzz....
So I've done some checking/testing and the battery is fine, I've tried another known good battery off my other mower, tried jumping it from my van, cleaned all electrical connections and earth points (I think), all of the above result in the same outcome though.
If I check the voltage (at battery, starter and solenoid) when I turn the key then it drops to 6v.....
So the big question, which is probably blindingly obvious but I can't see it, what do people think could be the problem and where should I start looking next ?
New starter motor maybe?
#7
S
slomo
S
slomo
I would look at the valves again before opening the case up checking on the compression relief. There are 2 TDC strokes on a 4 stroke engine. Could of set valves on wrong stroke. If you are certain valves are proper, cam inspection time.when I turn the key, the engine turns over about 1/4-1/2 of a revolution then stops dead and the starter starts to buzz....
Bad battery and or a flaky ground. Load test the battery at an auto parts store for free.If I check the voltage (at battery, starter and solenoid) when I turn the key then it drops to 6v
#8
S
slomo
Got a couple big rig 8D batteries for our work generator. $720.00 for a pair, 6 month warranty from Interstate. WOW.....
S
slomo
Most lawn batteries have a 6 month warranty. Just saying....that battery was bought brand new for that mower 5 months ago so would assume it's pretty decent still after that little time.
Got a couple big rig 8D batteries for our work generator. $720.00 for a pair, 6 month warranty from Interstate. WOW.....
#9
StarTech
StarTech
And Walmart batteries only have a 90 day warranty and I have seen them fail under warranty.
Starters when partially shorted out or are dragging on the magnets will draw excessive current. I replaced two this year where the owners were tapping in the starters with a hammer knocking the magnets loose. I wish they stop using old automobile tricks. A clamp current meter at the starter will tell if there is a problem with the starter, engine, wiring, or battery.
Troubleshooting electrical problems remotely is very challenging at the best; or at least is for me. I have my own testing procedure which includes voltage drop tests through out the wiring path. I have been working with circuits for over 40 yrs so the tests are pretty well ingrained in me.
Starters when partially shorted out or are dragging on the magnets will draw excessive current. I replaced two this year where the owners were tapping in the starters with a hammer knocking the magnets loose. I wish they stop using old automobile tricks. A clamp current meter at the starter will tell if there is a problem with the starter, engine, wiring, or battery.
Troubleshooting electrical problems remotely is very challenging at the best; or at least is for me. I have my own testing procedure which includes voltage drop tests through out the wiring path. I have been working with circuits for over 40 yrs so the tests are pretty well ingrained in me.
#10
C
CraigH
C
CraigH
Thanksbgor all the replies everyone.
I'm going to go try the battery again in abit, still on charge as I type this.
Electrics are my weak point with cars, etc.... I'm fine if you ask me to rebuild an engine or axle, but for some reason I've always found electronic stuff to be a nightmare.
Got to say, this is a very very good forum with some serious collective knowledge. I'm on a couple of other forums and wouldn't have had half the response in double the time on them!
I'm going to go try the battery again in abit, still on charge as I type this.
Electrics are my weak point with cars, etc.... I'm fine if you ask me to rebuild an engine or axle, but for some reason I've always found electronic stuff to be a nightmare.
Got to say, this is a very very good forum with some serious collective knowledge. I'm on a couple of other forums and wouldn't have had half the response in double the time on them!
#11
C
CraigH
C
CraigH
Right, so battery appears to be bad, charged on trickle charger all night (18 hours). It reads 12.8v at rest, turn the key with the plug out and lights off so no other drain on it and it reads a steady 9v. I'm guessing it should be higher than this with no load on it?
#12
S
slomo
New battery time.
S
slomo
Shouldn't drop below 10.5VDC WHILE cranking starter, spark plug in and ready to mow.Right, so battery appears to be bad, charged on trickle charger all night (18 hours). It reads 12.8v at rest, turn the key with the plug out and lights off so no other drain on it and it reads a steady 9v. I'm guessing it should be higher than this with no load on it?
New battery time.
#13
C
CraigH
C
CraigH
I'll get a new battery tomorrow hopefully and try that, them go from there.
Thanks for all the help so far.
Thanks for all the help so far.
#14
sgkent
sgkent
regardless any other problems, the battery is bad if flipping the lights on drops it to 9V. I have seen mechanics jump thru hoops trying to find an electrical problem because they believe a battery is good if the voltage is fine at rest. My Acura farted starting the other day, probably just the key fob but I had them check the battery capacity, and it was down to 60% so I replaced it. Just under 3 years old. Automotive batteries are 2 - 5 year life spans with the cars we have today. The battery in my battery backup for the computer failed the other day when the power went out. It is about 3 years old. How the USA will convert to battery from gasoline I have no idea. Going back to horses and oxen would make more sense. We could get to SF from NY by covered wagon again.
#15
I
ILENGINE
I
ILENGINE
Just saw an article last week were somebody in Florida has a 2014 Ford Escape EV that has a bad battery. Battery NLA, and if available would cost more than the vehicle is worth. So were does that vehicle end up now.regardless any other problems, the battery is bad if flipping the lights on drops it to 9V. I have seen mechanics jump thru hoops trying to find an electrical problem because they believe a battery is good if the voltage is fine at rest. My Acura farted starting the other day, probably just the key fob but I had them check the battery capacity, and it was down to 60% so I replaced it. Just under 3 years old. Automotive batteries are 2 - 5 year life spans with the cars we have today. The battery in my battery backup for the computer failed the other day when the power went out. It is about 3 years old. How the USA will convert to battery from gasoline I have no idea. Going back to horses and oxen would make more sense. We could get to SF from NY by covered wagon again.
#16
C
CraigH
C
CraigH
Quick question on the battery....
It has a 26ah battery on the mower, is this the correct one? It's got a code on it saying 101r 26ah. The same battery as my other mower but with the terminals reversed. Just want to make sure as after all the other problems I've found so far, it wouldn't surprise me to find it's the wrong battery anyway.
It has a 26ah battery on the mower, is this the correct one? It's got a code on it saying 101r 26ah. The same battery as my other mower but with the terminals reversed. Just want to make sure as after all the other problems I've found so far, it wouldn't surprise me to find it's the wrong battery anyway.
#17
S
slomo
Don't see how these wonder clean battery devices are saving the planet??
S
slomo
Same recipe as cordless drills and now 0-turn mowers. Battery NLA, throw the item on the curb.Just saw an article last week were somebody in Florida has a 2014 Ford Escape EV that has a bad battery. Battery NLA, and if available would cost more than the vehicle is worth. So were does that vehicle end up now.
Don't see how these wonder clean battery devices are saving the planet??
#18
B
bertsmobile1
B
bertsmobile1
99.9% of ride ons use the same battery ( thank heavens) and most have enough slack in the cable to take either a left or right hand terminals , MTD being about the sole exception where battery hand is importantQuick question on the battery....
It has a 26ah battery on the mower, is this the correct one? It's got a code on it saying 101r 26ah. The same battery as my other mower but with the terminals reversed. Just want to make sure as after all the other problems I've found so far, it wouldn't surprise me to find it's the wrong battery anyway.
#19
B
bertsmobile1
The no 1 problem is too many people but as every system of government and every economic theory relies on an ever increasing population getting that through peoples minds will be near impossible particularly when those who profit most by having excess population will be pouring buckets of money into keeping the status quo .
After that we all have to moderate our lifestyles quite substantially, remember walking in the woods & camping for holidays and a "once in a lifetime " trip overseas ?
The fact that the EV makers are all pushing their product as the only solution , for no other reason than their personal greed shows that nothing has actually changed .
Hydrogen powered vehicles are the only truely green solution to transport apart from leg power, and only then if the hydrogen is from solar electrolysis of water .
I had hoped when the first Tesla Time Bomb burst into flames last year down here we might have rethought battery storage & gone with safer flow cell technology but no they are replacing it with a bigger one . Are we really the most intelligent species on the planet ?
Try keeping one under 85 deg C when the surrounding air is 40 + deg C
Back in my college days I remember all of the exciting work being done in medicine and the promise that we were on the cusp of being the last generation to die from "old age".
There were also some physists warning that if we keep on polluting the way we were then we could be the last generation to walk the planet .( no climate scientists in those days)
Looks very much like the latter will overcome the former .
We are getting ready for the 5th flood down the East Coast this season with the promise of a couple more when the spring rains come .
There was 2 floods in the previous 15 years that I have been here and both were minor.
The 4 this year have all been major or above major.
B
bertsmobile1
They are a con to allow the sinners to go on sinning with a clean conscience .Same recipe as cordless drills and now 0-turn mowers. Battery NLA, throw the item on the curb.
Don't see how these wonder clean battery devices are saving the planet??
The no 1 problem is too many people but as every system of government and every economic theory relies on an ever increasing population getting that through peoples minds will be near impossible particularly when those who profit most by having excess population will be pouring buckets of money into keeping the status quo .
After that we all have to moderate our lifestyles quite substantially, remember walking in the woods & camping for holidays and a "once in a lifetime " trip overseas ?
The fact that the EV makers are all pushing their product as the only solution , for no other reason than their personal greed shows that nothing has actually changed .
Hydrogen powered vehicles are the only truely green solution to transport apart from leg power, and only then if the hydrogen is from solar electrolysis of water .
I had hoped when the first Tesla Time Bomb burst into flames last year down here we might have rethought battery storage & gone with safer flow cell technology but no they are replacing it with a bigger one . Are we really the most intelligent species on the planet ?
Try keeping one under 85 deg C when the surrounding air is 40 + deg C
Back in my college days I remember all of the exciting work being done in medicine and the promise that we were on the cusp of being the last generation to die from "old age".
There were also some physists warning that if we keep on polluting the way we were then we could be the last generation to walk the planet .( no climate scientists in those days)
Looks very much like the latter will overcome the former .
We are getting ready for the 5th flood down the East Coast this season with the promise of a couple more when the spring rains come .
There was 2 floods in the previous 15 years that I have been here and both were minor.
The 4 this year have all been major or above major.
#20
R
RayMcD
R
RayMcD
Craig, a battery should never drop below it's rated voltage. If it does likely it has a bad cell and it's time for a new one. Typical lead acid battery is ~2.2 volts per cell, 12volt lead acid battery at full charge will ready ~13 volts, if it drops below 12 volts it's time to replace. Cheers RayRight, so battery appears to be bad, charged on trickle charger all night (18 hours). It reads 12.8v at rest, turn the key with the plug out and lights off so no other drain on it and it reads a steady 9v. I'm guessing it should be higher than this with no load on it?
#21
S
slomo
S
slomo
Normally it's 12.6 at full charge but I like me some 13 too.Craig, a battery should never drop below it's rated voltage. If it does likely it has a bad cell and it's time for a new one. Typical lead acid battery is ~2.2 volts per cell, 12volt lead acid battery at full charge will ready ~13 volts, if it drops below 12 volts it's time to replace. Cheers Ray
#22
C
CraigH
C
CraigH
O k ..... So new battery bought and charged just to make sure it wasn't flat/low from the shop. Its a 12v 30ah 330cca so plenty powerful enough, but the result was the same as before, the engine tried to turn but only goes about half a rev then locks.
I'm pretty sure what someone mentioned earlier must be the fault now, the cam!
I'm pretty sure what someone mentioned earlier must be the fault now, the cam!
#23
sgkent
sgkent
does it spin freely with the plugs out?
#24
C
CraigH
C
CraigH
Yep, spins over fine with no plug in.
Battery reads 12.8v then when I turn the key with the plug out it reads 10.8v
Battery reads 12.8v then when I turn the key with the plug out it reads 10.8v
#25
sgkent
sgkent
where are you reading the voltage between?Yep, spins over fine with no plug in.
Battery reads 12.8v then when I turn the key with the plug out it reads 10.8v
#28
C
CraigH
C
CraigH
I'm guessing they should all read the same when cranking, otherwise I'll have an earth issue? Will try to check it in abit but not sure if I'll have a chance today.
I've already checked and cleaned all electrical connections, removed and cleaned where the earth lead from battery is bolted to the chassis, cleaned starter and checked it's got a good live connection, also cleaned the mounting plate for it as that's what earth's it to the engine, I've also removed the starter solenoid and cleaned the surface where it mounts to give the best earth possible there too aswell as cleaning the live leads on it.
I just keep coming back to the cam again and again now, the engine just acts like it's got too much compression when cranking it.
I've already checked and cleaned all electrical connections, removed and cleaned where the earth lead from battery is bolted to the chassis, cleaned starter and checked it's got a good live connection, also cleaned the mounting plate for it as that's what earth's it to the engine, I've also removed the starter solenoid and cleaned the surface where it mounts to give the best earth possible there too aswell as cleaning the live leads on it.
I just keep coming back to the cam again and again now, the engine just acts like it's got too much compression when cranking it.
#29
sgkent
sgkent
if the fully charged new battery BETWEEN POSTS is dropping to 10.8V at the terminals when the plugs are out, my instinct tells me you have a bad starter. Now that I have said that, maybe someone who works on these for a living can confirm that or not. Normally most engines have very little load when the plugs are out. Unfortunately most people do not have a clamp on DC ampmeter that can read starter current. Most clamp on meters are AC. But if you have access to a DC clamp on ammeter in the range needed, try measuring the current. Most likely it will be excessively high. If the engine turns easily by hand then the only thing left would be excessive current in the starter motor. If the engine turns hard with the plugs out by hand, then one would wonder why the engine is so hard to turn.Voltage taken at battery terminals.
#30
sgkent
sgkent
I might add, you can ignore bad grounds and cables right now if the post to post voltage is 10.8V. When I say post to post, I literally mean post to post, and not terminal to post or cable to cable etc. Post to post is between the actual connectors that are a part of the battery.
#31
C
CraigH
C
CraigH
Yep, reading taken at posts at the he closest point to where they enter the battery body.
Sadly I don't have an ammeter, just a digital multimeter.
Sadly I don't have an ammeter, just a digital multimeter.
#32
sgkent
sgkent
Maybe Bert, Walt, Star Tech or one of the other techs here could tell you if that is normal or not on a new battery. A 2V drop sounds excessive to me - like the starter is pulling too much current. Unless the engine is hard to turn by hand with the plugs out. I would think it would just spin like crazy when the plugs are out. This assumes that the PTO belt is somehow not engaged.
#33
S
slomo
S
slomo
Excessive amp draw with no spark plug in. Should be about that ready to mow, 10.8vdc while cranking.Battery reads 12.8v then when I turn the key with the plug out it reads 10.8v
#34
B
bertsmobile1
B
bertsmobile1
Way back in reply #1 it was suggested that the compression release was probably the problem
Then in reply # 7 the cam was again suggested to be the villian .
Then the thread wandered off because of numbers on a DVM
I never use one apart to test the output from the alternator & diodes as numbers just confuse things as has happened here because people do not understand the significance of the numbers.
In your case the 2 minute test which you had already done is to get a pair of jumpers and a known good battery , ie your vehicle .
You then bypass your mowers wiring by jumping directly from the battery to the starter motor
If the starter fails to turn over the engine then you do the same from the known good battery
As that failed to turn over the engine then either the starter is bad or the cam is bad , which is why Illengine suggested the cam back in reply # 1
The 2 minute test for a bad cam / mal adjusted valve lash is to try cranking without the spark plug as you had done .
So cranks no plugs won't crank with plugs = reset valve lash carefully & try again.
Same results = stuffed cam
You verify the cam by removing the rocker cover , adjusting the valve lash then rotate the engine watching the rockers .
In your case the inlet should reopen a tiny amount just before the piston gets to the end of the cylinder .
To check the compression relief against wear, you close down the inlet valve lash.
You can go as tight as 0.002" without seriously affecting the performance of the engine, but that is of course a stop gap to get you by till the new cam arrives or till the end of the season
AS for dropping battery voltage under heavy discharge, this is quite normal and happens when the current draw exceeds the discharge rate of the battery
The discharge rate is a function of the plate geometry & metallurgy , the paste chemistry & grain size, the bonding agent used for the paste, the electrolyte & the busbars that connect all the plates together and the temperature of the battery & wires .
The main purpose of carbon pile load testers is to sell confused customers new batteries and I am yet to see an auto parts store use one correctly .
Most mowers use # 4 ( Top end ) # 6 ( bulk of brands ) or # 8 ( cheapies ) gauge wire, usually 25 to 42 strand .
The current capacity of that wire is roughly 45A, 35A or 25A respectively so shoving a 200 +A load from a carbon pile across the terminals is pointless because the wires can not carry that load and the starter will never draw those sort of amps unless there is a dead short .
Then in reply # 7 the cam was again suggested to be the villian .
Then the thread wandered off because of numbers on a DVM
I never use one apart to test the output from the alternator & diodes as numbers just confuse things as has happened here because people do not understand the significance of the numbers.
In your case the 2 minute test which you had already done is to get a pair of jumpers and a known good battery , ie your vehicle .
You then bypass your mowers wiring by jumping directly from the battery to the starter motor
If the starter fails to turn over the engine then you do the same from the known good battery
As that failed to turn over the engine then either the starter is bad or the cam is bad , which is why Illengine suggested the cam back in reply # 1
The 2 minute test for a bad cam / mal adjusted valve lash is to try cranking without the spark plug as you had done .
So cranks no plugs won't crank with plugs = reset valve lash carefully & try again.
Same results = stuffed cam
You verify the cam by removing the rocker cover , adjusting the valve lash then rotate the engine watching the rockers .
In your case the inlet should reopen a tiny amount just before the piston gets to the end of the cylinder .
To check the compression relief against wear, you close down the inlet valve lash.
You can go as tight as 0.002" without seriously affecting the performance of the engine, but that is of course a stop gap to get you by till the new cam arrives or till the end of the season
AS for dropping battery voltage under heavy discharge, this is quite normal and happens when the current draw exceeds the discharge rate of the battery
The discharge rate is a function of the plate geometry & metallurgy , the paste chemistry & grain size, the bonding agent used for the paste, the electrolyte & the busbars that connect all the plates together and the temperature of the battery & wires .
The main purpose of carbon pile load testers is to sell confused customers new batteries and I am yet to see an auto parts store use one correctly .
Most mowers use # 4 ( Top end ) # 6 ( bulk of brands ) or # 8 ( cheapies ) gauge wire, usually 25 to 42 strand .
The current capacity of that wire is roughly 45A, 35A or 25A respectively so shoving a 200 +A load from a carbon pile across the terminals is pointless because the wires can not carry that load and the starter will never draw those sort of amps unless there is a dead short .
#35
sgkent
sgkent
Bert - his engine does not make it a full turn with a new battery fully charged and the plugs removed. The voltage falls to 10.2V at the actual battery terminals. To me that sounds like excessive draw at the starter. With the plugs removed and measuring at the actual terminals, I don't see how the cam or cables could be of issue. He has not confirmed that the engine turns freely by hand, or I missed it.
#36
B
bertsmobile1
But he has used jumpers from a known good battery which made no difference.
IF a starter is energised but does not turn then the armature is a direct short across the battery so the voltage will drop .
B
bertsmobile1
Actually , my bad got this one mixed up with another one.Bert - his engine does not make it a full turn with a new battery fully charged and the plugs removed. The voltage falls to 10.2V at the actual battery terminals. To me that sounds like excessive draw at the starter. With the plugs removed and measuring at the actual terminals, I don't see how the cam or cables could be of issue. He has not confirmed that the engine turns freely by hand, or I missed it.
But he has used jumpers from a known good battery which made no difference.
IF a starter is energised but does not turn then the armature is a direct short across the battery so the voltage will drop .
#37
S
slomo
Get the lowest CCA rating you can. Should have thicker lead plates providing longer battery life. Case in point, the battery picture from walmart. They have the same mower battery in 330 and 230cca's. Get the 230cca battery.
S
slomo
Get one like this. Must fit in your battery tray. Same terminals are easy to match up at battery store. Or look in your manual for proper battery part number/type.Quick question on the battery....
It has a 26ah battery on the mower, is this the correct one? It's got a code on it saying 101r 26ah. The same battery as my other mower but with the terminals reversed. Just want to make sure as after all the other problems I've found so far, it wouldn't surprise me to find it's the wrong battery anyway.
Get the lowest CCA rating you can. Should have thicker lead plates providing longer battery life. Case in point, the battery picture from walmart. They have the same mower battery in 330 and 230cca's. Get the 230cca battery.
#38
S
slomo
S
slomo
Pull the starter off the engine. Bench test it with a jump pack and jumper cables. Measure the voltage drop when cranking. Should be minimal with heavy gauge cables and a large battery source. If you are still getting 9 and 10vdc in free air, starter is toast.
Also measure voltage drop across starter solenoid, while cranking. Contacts could be getting smoked drawing excessive current.
Also measure voltage drop across starter solenoid, while cranking. Contacts could be getting smoked drawing excessive current.
#39
C
CraigH
C
CraigH
The engine spins over absolutely fine with the plug removed.Bert - his engine does not make it a full turn with a new battery fully charged and the plugs removed. The voltage falls to 10.2V at the actual battery terminals. To me that sounds like excessive draw at the starter. With the plugs removed and measuring at the actual terminals, I don't see how the cam or cables could be of issue. He has not confirmed that the engine turns freely by hand, or I missed it.
#40
C
CraigH
C
CraigH
As mentioned a few posts back, I've replaced battery with a u1r 12v 30ah 330cca, it's all I could get as we don't have alot of choice off the shelf in this country like you may do, ride on mowers and ATVs (which use these batteries) aren't very common over here hence the lack of support from my side of the pond.Get one like this. Must fit in your battery tray. Same terminals are easy to match up at battery store. Or look in your manual for proper battery part number/type.
Get the lowest CCA rating you can. Should have thicker lead plates providing longer battery life. Case in point, the battery picture from walmart. They have the same mower battery in 330 and 230cca's. Get the 230cca battery.
View attachment 61666
#41
C
CraigH
So I can close the inlet valve clearance to 0.002" and this should have the same affect as what the cam decompression system does? If so, I'll try that later today.
Ill test the starter on the bench later aswell and report back. But as you've said, I've linled it all up to my van with a 2.2 diesel engine (running) and this had no effect on starting the mower which is why I've kept coming back to the cam decompression, or bad starter. I'm leaning towards cam decompression and if that's not the case, I'll get a new starter (starter is the most expensive item at £80-180 depending on brand).
C
CraigH
Way back in reply #1 it was suggested that the compression release was probably the problem
Then in reply # 7 the cam was again suggested to be the villian .
Then the thread wandered off because of numbers on a DVM
I never use one apart to test the output from the alternator & diodes as numbers just confuse things as has happened here because people do not understand the significance of the numbers.
In your case the 2 minute test which you had already done is to get a pair of jumpers and a known good battery , ie your vehicle .
You then bypass your mowers wiring by jumping directly from the battery to the starter motor
If the starter fails to turn over the engine then you do the same from the known good battery
As that failed to turn over the engine then either the starter is bad or the cam is bad , which is why Illengine suggested the cam back in reply # 1
The 2 minute test for a bad cam / mal adjusted valve lash is to try cranking without the spark plug as you had done .
So cranks no plugs won't crank with plugs = reset valve lash carefully & try again.
Same results = stuffed cam
You verify the cam by removing the rocker cover , adjusting the valve lash then rotate the engine watching the rockers .
In your case the inlet should reopen a tiny amount just before the piston gets to the end of the cylinder .
To check the compression relief against wear, you close down the inlet valve lash.
You can go as tight as 0.002" without seriously affecting the performance of the engine, but that is of course a stop gap to get you by till the new cam arrives or till the end of the season
AS for dropping battery voltage under heavy discharge, this is quite normal and happens when the current draw exceeds the discharge rate of the battery
The discharge rate is a function of the plate geometry & metallurgy , the paste chemistry & grain size, the bonding agent used for the paste, the electrolyte & the busbars that connect all the plates together and the temperature of the battery & wires .
The main purpose of carbon pile load testers is to sell confused customers new batteries and I am yet to see an auto parts store use one correctly .
Most mowers use # 4 ( Top end ) # 6 ( bulk of brands ) or # 8 ( cheapies ) gauge wire, usually 25 to 42 strand .
The current capacity of that wire is roughly 45A, 35A or 25A respectively so shoving a 200 +A load from a carbon pile across the terminals is pointless because the wires can not carry that load and the starter will never draw those sort of amps unless there is a dead short .
So I can close the inlet valve clearance to 0.002" and this should have the same affect as what the cam decompression system does? If so, I'll try that later today.
Ill test the starter on the bench later aswell and report back. But as you've said, I've linled it all up to my van with a 2.2 diesel engine (running) and this had no effect on starting the mower which is why I've kept coming back to the cam decompression, or bad starter. I'm leaning towards cam decompression and if that's not the case, I'll get a new starter (starter is the most expensive item at £80-180 depending on brand).
#42
I
ILENGINE
I
ILENGINE
Just keep in mind that the issue could be a combination of both items. If the decompression has been broke for some time, or in in some cases the valves out of adjustment and the starter is forced to overcome that resistance over time will damage the starter.So I can close the inlet valve clearance to 0.002" and this should have the same affect as what the cam decompression system does? If so, I'll try that later today.
Ill test the starter on the bench later aswell and report back. But as you've said, I've linled it all up to my van with a 2.2 diesel engine (running) and this had no effect on starting the mower which is why I've kept coming back to the cam decompression, or bad starter. I'm leaning towards cam decompression and if that's not the case, I'll get a new starter (starter is the most expensive item at £80-180 depending on brand).
#43
C
CraigH
This mower is turning into abit of a nightmare, but hopefully it'll be worth the hassle (and expense) when it's all running sweet soon.
C
CraigH
Thanks for that, that's a good point, the valves were miles out of adjustment when I took the rocker cover off originally, so could be an overworked starter too.Just keep in mind that the issue could be a combination of both items. If the decompression has been broke for some time, or in in some cases the valves out of adjustment and the starter is forced to overcome that resistance over time will damage the starter.
This mower is turning into abit of a nightmare, but hopefully it'll be worth the hassle (and expense) when it's all running sweet soon.
#44
S
slomo
Set the valves yearly for a good running engine. Only takes a few minutes. Good winter time project when you are not mowing.
S
slomo
Ah ha.the valves were miles out of adjustment when I took the rocker cover off originally
Set the valves yearly for a good running engine. Only takes a few minutes. Good winter time project when you are not mowing.
#45
C
CraigH
I'll have a look at the valves later and see if I can get it to turn over properly if the 0.002" clearance trick is a good test to try?
Is there any other ways to test if the cam is bad?
Also, a bench test on the starter, what sort of voltage figure should I be aiming for? 12v?
C
CraigH
Was going to fix this one up as a winter project but been off work for the last 10 days with COVID so figured, why not get on with it now as I've had plenty of time on my hands (well, I say plenty of time, I've been looking after little one aswell as trying to get a few mins spare to have a look at the mower and test bits).Ah ha.
Set the valves yearly for a good running engine. Only takes a few minutes. Good winter time project when you are not mowing.
I'll have a look at the valves later and see if I can get it to turn over properly if the 0.002" clearance trick is a good test to try?
Is there any other ways to test if the cam is bad?
Also, a bench test on the starter, what sort of voltage figure should I be aiming for? 12v?
#46
S
slomo
More explanation, I messed the above up. You should have full static battery voltage testing in free air. If you are voltage drop testing, should read close to 0vdc drop. Two ways of testing here. Voltage drop method ON the mower is the best method while under load, cranking the starter.
Don't forget to inspect your ground cable end to end. Polish the connectors up and mounting points.
S
slomo
Remove valve cover. Watch the valves as you rotate the engine. Both valves should move roughly the same at different times of course. Oh pull the plug out to turn the crank easier.Is there any other ways to test if the cam is bad?
A starter in free air, unmounted, should measure full or darn near full battery voltage. As in "basically" no voltage drop. Battery should be 12vdc or higher while cranking in free air on the bench. Good battery and cables........Also, a bench test on the starter, what sort of voltage figure should I be aiming for? 12v?
More explanation, I messed the above up. You should have full static battery voltage testing in free air. If you are voltage drop testing, should read close to 0vdc drop. Two ways of testing here. Voltage drop method ON the mower is the best method while under load, cranking the starter.
Don't forget to inspect your ground cable end to end. Polish the connectors up and mounting points.
#47
C
CraigH
C
CraigH
Thanks for the help/pointers above.
I set inlet valve to 0.002" with piston 1/4" down from tdc. The engine turned over marginally better than before but still wouldn't make a full revolution with the plug in and a fully charged battery.
Next was to bench test the starter.
I fully charged the battery again and was getting 12.8v on the multimeter with nothing connected to the battery at all.
I used some heavy jump leads and tested the starter, connecting the earth lead to the mounting plate at the top of the starter and the positive lead to the terminal on the side where the positive lead bolts to, the voltage when the starter was spinning (I tried it 3 times for 5 second bursts) was 12.2v across the terminals on the battery.
So, what would people recommend my next step should be?
Time for a new starter? If so, what would you recommend? Aftermarket or genuine?
Do you think the cam decompression system is broken?
I set inlet valve to 0.002" with piston 1/4" down from tdc. The engine turned over marginally better than before but still wouldn't make a full revolution with the plug in and a fully charged battery.
Next was to bench test the starter.
I fully charged the battery again and was getting 12.8v on the multimeter with nothing connected to the battery at all.
I used some heavy jump leads and tested the starter, connecting the earth lead to the mounting plate at the top of the starter and the positive lead to the terminal on the side where the positive lead bolts to, the voltage when the starter was spinning (I tried it 3 times for 5 second bursts) was 12.2v across the terminals on the battery.
So, what would people recommend my next step should be?
Time for a new starter? If so, what would you recommend? Aftermarket or genuine?
Do you think the cam decompression system is broken?
#48
C
CraigH
C
CraigH
Forgot to mention, cam moves both valves around an equal amount (judging by eye) so the cam appears to be o.k, not sure how to test the decompression system on it further though.
#49
I
ILENGINE
I
ILENGINE
With the plug out, turn the engine over by hand while observing the bottom valve which on the single OHV engine is the intake valve. After the intake valve closes and you turn the engine and the piston comes toward TDC you should see the intake valve bump off of the seat slightly and then close as the piston hits TDC. That bump is the decompressor. No bump which I suspect in this case will me time to open up the engine.Forgot to mention, cam moves both valves around an equal amount (judging by eye) so the cam appears to be o.k, not sure how to test the decompression system on it further though.
#50
sgkent
sgkent
THE ENGINE MUST BE ABLE TO SPIN FREELY 360 DEGREES MULTIPLE REVOLUTIONS WITH THE PLUGS OUT BOTH BY HAND AND STARTER BEFORE GOING FURTHER. There is no compression when the plugs are out.
to have 12.2V while spinning the starter, and 12.8V at rest, would be within a normal voltage drop I think. Why the engine can turn freely by hand when the plugs are out but load the battery so much when the starter is used with the plugs out is beyond me.
Until the engine spins freely with the plugs out, doing other adjustments, etc., taking an engine apart is just wasted time in my eyes.
ONE TEST might be to spin the engine by hand several revolutions with the plugs out. Disconnect the starter wire and tape it out of the way so not to short or cause another issue. Turn the key to start and see if the engine still spins freely by hand. Would a shorted alternator winding bind the engine enough and pull the voltage down? What if the PTO was wired to full on when the engine was starting and the belt was binding. Need to be sure the engine will spin freely by hand in the start position. The voltage should not fall much in the start position when the starter or starter wire is removed.
to have 12.2V while spinning the starter, and 12.8V at rest, would be within a normal voltage drop I think. Why the engine can turn freely by hand when the plugs are out but load the battery so much when the starter is used with the plugs out is beyond me.
Until the engine spins freely with the plugs out, doing other adjustments, etc., taking an engine apart is just wasted time in my eyes.
ONE TEST might be to spin the engine by hand several revolutions with the plugs out. Disconnect the starter wire and tape it out of the way so not to short or cause another issue. Turn the key to start and see if the engine still spins freely by hand. Would a shorted alternator winding bind the engine enough and pull the voltage down? What if the PTO was wired to full on when the engine was starting and the belt was binding. Need to be sure the engine will spin freely by hand in the start position. The voltage should not fall much in the start position when the starter or starter wire is removed.
#51
C
CraigH
The PTO is not engaged and the belt is off.
C
CraigH
Yes, the engine spins multiple revolutions very freely using the starter with the spark plug out. It's when the spark plug is in that it seems to have too much compression and won't spin a full revolution.THE ENGINE MUST BE ABLE TO SPIN FREELY 360 DEGREES MULTIPLE REVOLUTIONS WITH THE PLUGS OUT BOTH BY HAND AND STARTER BEFORE GOING FURTHER. There is no compression when the plugs are out.
to have 12.2V while spinning the starter, and 12.8V at rest, would be within a normal voltage drop I think. Why the engine can turn freely by hand when the plugs are out but load the battery so much when the starter is used with the plugs out is beyond me.
Until the engine spins freely with the plugs out, doing other adjustments, etc., taking an engine apart is just wasted time in my eyes.
ONE TEST might be to spin the engine by hand several revolutions with the plugs out. Disconnect the starter wire and tape it out of the way so not to short or cause another issue. Turn the key to start and see if the engine still spins freely by hand. Would a shorted alternator winding bind the engine enough and pull the voltage down? What if the PTO was wired to full on when the engine was starting and the belt was binding. Need to be sure the engine will spin freely by hand in the start position. The voltage should not fall much in the start position when the starter or starter wire is removed.
The PTO is not engaged and the belt is off.
#52
C
CraigH
C
CraigH
I'll try that tomorrow morning and report back, thanks for the advice.With the plug out, turn the engine over by hand while observing the bottom valve which on the single OHV engine is the intake valve. After the intake valve closes and you turn the engine and the piston comes toward TDC you should see the intake valve bump off of the seat slightly and then close as the piston hits TDC. That bump is the decompressor. No bump which I suspect in this case will me time to open up the engine.
#53
sgkent
edit (added):
That said, I read back over your notes and I believe you said that with the plugs out on a new fully charged battery, the voltage falls to 10.8V. That seems about .75 to 1V low. It implies either a weak battery or excessive current draw. Then I think you said the starter only drops the voltage to 12.2V when the starter is out of the engine. While the decompression feature may be the cause of it not spinning, you may have other issues in the electrical system once you get it spinning. If the engineers designed that much voltage drop it is a poor design. Many later automotive FI systems won't work when voltages fall that low. Here in California the new small engines are going to require FI and catalytic converters. Will be interesting if cranking systems drop that low.
sgkent
if that is the case, then the suggestions that the decompression feature is not working sounds correct.Yes, the engine spins multiple revolutions very freely using the starter with the spark plug out. It's when the spark plug is in that it seems to have too much compression and won't spin a full revolution.
The PTO is not engaged and the belt is off.
edit (added):
That said, I read back over your notes and I believe you said that with the plugs out on a new fully charged battery, the voltage falls to 10.8V. That seems about .75 to 1V low. It implies either a weak battery or excessive current draw. Then I think you said the starter only drops the voltage to 12.2V when the starter is out of the engine. While the decompression feature may be the cause of it not spinning, you may have other issues in the electrical system once you get it spinning. If the engineers designed that much voltage drop it is a poor design. Many later automotive FI systems won't work when voltages fall that low. Here in California the new small engines are going to require FI and catalytic converters. Will be interesting if cranking systems drop that low.
#54
C
CraigH
C
CraigH
Thanks for all the help with this.
I finally got round to pulling the engine out last night to have a look at, safe to say I think it's completely shafted!
What I assumed was going to be a small problem with the starter has turned into a whole different story.
When I got the engine unbolted and laid it on the bench it sounded like a tin can filled with nails, not a great sign I figured.... Once I opened it up, I discovered alot of parts rattling around, the counter weight links are both in lots of small pieces, aswell as a white plastic cog thats smashed and a few bent springs.
If I can figure out how to post a pic I will try to later.
Now I'm wondering if it's worth the hassle of rebuilding or do I find a suitable replacement engine?
Ive had a look for that engine online and can't find any for sale so would a similar Briggs and Stratton engine with the same power work?
I finally got round to pulling the engine out last night to have a look at, safe to say I think it's completely shafted!
What I assumed was going to be a small problem with the starter has turned into a whole different story.
When I got the engine unbolted and laid it on the bench it sounded like a tin can filled with nails, not a great sign I figured.... Once I opened it up, I discovered alot of parts rattling around, the counter weight links are both in lots of small pieces, aswell as a white plastic cog thats smashed and a few bent springs.
If I can figure out how to post a pic I will try to later.
Now I'm wondering if it's worth the hassle of rebuilding or do I find a suitable replacement engine?
Ive had a look for that engine online and can't find any for sale so would a similar Briggs and Stratton engine with the same power work?