Export thread

Engine lets out a puff of smoke but doesn't even sputter when attempting to start

#1

J

jetpackjbd

Hi, my 2002 riding mower has a 13 horsepower B&S engine. It's been running fine and starting instantly. I shut it off and went to turn it on a minute later, and it refused to do anything. It wouldn't even spin. After turning it with a torque wrench for a bit, it became loose and spun easily. The oil was mostly clear and was at the full mark. Replaced the fuel filter and spark plug and got it to give off a single puff of smoke, but that was it. Even with starting fluid, nothing changed. The battery is under a year old and is at normal voltage. Really hoping the engine isn't toast...


#2

B

bertsmobile1

Take the rocker cover off & check that all of the push rods are there
When the valve lash gets really sloppy the rocker can fall off then the rod fall into the engine
Some times they just sit there & some times they lock up the engine
If it has fallen in & gotten chewed up you will have to split the engine to find all of the little bits as a very small piece of debris can jamb the governor then it is zoooom BANG


#3

J

jetpackjbd

bertsmobile1 said:
Take the rocker cover off & check that all of the push rods are there
When the valve lash gets really sloppy the rocker can fall off then the rod fall into the engine
Some times they just sit there & some times they lock up the engine
If it has fallen in & gotten chewed up you will have to split the engine to find all of the little bits as a very small piece of debris can jamb the governor then it is zoooom BANG
Click to expand...
Will do soon, hoping this isn't the case. I assume if it is, then it's probably time to get a new mower.


#4

J

jetpackjbd

bertsmobile1 said:
Take the rocker cover off & check that all of the push rods are there
When the valve lash gets really sloppy the rocker can fall off then the rod fall into the engine
Some times they just sit there & some times they lock up the engine
If it has fallen in & gotten chewed up you will have to split the engine to find all of the little bits as a very small piece of debris can jamb the governor then it is zoooom BANG
Click to expand...
Just remembered the engine is non-ohv, so it has no pushrods, right?


#5

sgkent

sgkent

try it with the spark plug(s) out to see if it spins.


#6

B

bertsmobile1

Sounds like the engine is toast
Had you been driving along a slope just before you stopped ?
To check that it is in fact an engine problem, pull both belts from the engine pulley
A jambed up belt can slow the cranking down just enough to prevent the engine from starting


#7

J

jetpackjbd

sgkent said:
try it with the spark plug(s) out to see if it spins.
Click to expand...
I already got it spinning freely, sorry if I hadn't made that clear in the original post


#8

J

jetpackjbd

bertsmobile1 said:
Sounds like the engine is toast
Had you been driving along a slope just before you stopped ?
To check that it is in fact an engine problem, pull both belts from the engine pulley
A jambed up belt can slow the cranking down just enough to prevent the engine from starting
Click to expand...
I was driving up a mild slope, but it was far under 15 degrees. I've made sure to clean the deck and belt area every other week, and made sure to do so before attempting to service. I can freely turn the belt by hand and the engine by hand, but I can try removing the belt if you think that'll help. I should mention the reason I turned the engine off originally was that I couldn't go into reverse for whatever reason, so it's likely there's some belt issue


#9

B

bertsmobile1

It is a case of elimination
By removing the belts we eliminate the mower putting a drag on the engine
When running along a slope it is easy to have the oil pick up in the air so the oil pump is pumping foam or just air
The top bushing area has a small dam of oil and if it is not kept full then the crankshaft can sieze in the crankcase
Or the starter motor can jamb which normally releases by rotating the flywheel backwards.
A 2002 model is well past its use by date but we are here to fix things if that is at all possible
Usually side valve engines loose valve lash on the exhaust because the valve seat burns away
All side valve engines do this and when it gets chronic the exhaust valve no longer seals
It is a PIA on side bangers to check because the valve chest is behind the carburettor.
In the workshop I have both a bore-o-scope & a leak down tester to check for this .

If the valves can close & the timing is good then the engine will fire when you put fuel down the plug hole
If it does not fire then either the valves are not sealing or the flywheel has spun on the crankshaft so the spark is out of time
or the piston is no longer going up & down.( check with a pencil poked down the plug hole .)


If the engine had a temporary seizure & you forced it free by turning the flywheel then there is a good chance the timing key broke or the con rod broke

So try what has been sugested and come back


#10

J

jetpackjbd

bertsmobile1 said:
It is a case of elimination
By removing the belts we eliminate the mower putting a drag on the engine
When running along a slope it is easy to have the oil pick up in the air so the oil pump is pumping foam or just air
The top bushing area has a small dam of oil and if it is not kept full then the crankshaft can sieze in the crankcase
Or the starter motor can jamb which normally releases by rotating the flywheel backwards.
A 2002 model is well past its use by date but we are here to fix things if that is at all possible
Usually side valve engines loose valve lash on the exhaust because the valve seat burns away
All side valve engines do this and when it gets chronic the exhaust valve no longer seals
It is a PIA on side bangers to check because the valve chest is behind the carburettor.
In the workshop I have both a bore-o-scope & a leak down tester to check for this .

If the valves can close & the timing is good then the engine will fire when you put fuel down the plug hole
If it does not fire then either the valves are not sealing or the flywheel has spun on the crankshaft so the spark is out of time
or the piston is no longer going up & down.( check with a pencil poked down the plug hole .)


If the engine had a temporary seizure & you forced it free by turning the flywheel then there is a good chance the timing key broke or the con rod broke

So try what has been sugested and come back
Click to expand...
-It can't hurt removing the belt, I'll try that from now on
-The starter motor is good: it spins, goes up when starting, and goes back down when off.
-Unsure of the valve condition, will check
-I think the con rod is fine, I can feel some compression and see the piston moving up and down.
-The timing key/magnet is quite rusty but is still magnetic and hasn't broken. It's possible it became offset though, however it doesn't seem to fire at all, forget misfiring.

In a bit I'll try removing the belt, putting fuel directly in the spark plug hole, then checking the valves.

I've also seen people have a similar starting issue, which is caused by safety switches which prevent the engine starting if the deck is down for example. The switches can get stuck and make it think it's still down when it's up. I've tried starting it while one of the switches is disconnected, no luck, but there may be other switches I'm unaware of.


#11

J

jetpackjbd

Narrowed it down to the magneto, ordering a new one. Hope this fixes it, only thing that would make sense.


#12

S

slomo

Air, spark, fuel and compression. Back to the basics.

Any and all new parts will require testing. New is not new these days.

Most likely the carb and fuel system is filthy. Valves never been checked. Block cooling fins neglected as in never cleaned or looked at.


#13

S

slomo

jetpackjbd said:
Narrowed it down to the magneto, ordering a new one. Hope this fixes it, only thing that would make sense.
Click to expand...
New mag will need to be LOAD tested. As in taking an old plug. Gap to 1/4" or 0.250", super wide. Ground the threads and check for healthy spark.


#14

J

jetpackjbd

slomo said:
New mag will need to be LOAD tested. As in taking an old plug. Gap to 1/4" or 0.250", super wide. Ground the threads and check for healthy spark.
Click to expand...
Will do, but for now I'll just be happy to get any spark at all...


#15

J

jetpackjbd

I've got spark! But I think my old magneto may have been fine...
I took off the carburetor today and sprayed starting fluid directly into the hole where the carburetor would connect. Ended up with a tiny fire and an engine that still showed no signs of life...


#16

S

slomo

So you have air, fuel and spark. Still no signs of life. Remaining factor is compression. Time to open her up to check valves and piston/rod.


#17

J

jetpackjbd

bertsmobile1 said:
It is a case of elimination
By removing the belts we eliminate the mower putting a drag on the engine
When running along a slope it is easy to have the oil pick up in the air so the oil pump is pumping foam or just air
The top bushing area has a small dam of oil and if it is not kept full then the crankshaft can sieze in the crankcase
Or the starter motor can jamb which normally releases by rotating the flywheel backwards.
A 2002 model is well past its use by date but we are here to fix things if that is at all possible
Usually side valve engines loose valve lash on the exhaust because the valve seat burns away
All side valve engines do this and when it gets chronic the exhaust valve no longer seals
It is a PIA on side bangers to check because the valve chest is behind the carburettor.
In the workshop I have both a bore-o-scope & a leak down tester to check for this .

If the valves can close & the timing is good then the engine will fire when you put fuel down the plug hole
If it does not fire then either the valves are not sealing or the flywheel has spun on the crankshaft so the spark is out of time
or the piston is no longer going up & down.( check with a pencil poked down the plug hole .)


If the engine had a temporary seizure & you forced it free by turning the flywheel then there is a good chance the timing key broke or the con rod broke

So try what has been sugested and come back
Click to expand...
Whelp, you were right. I finally took the engine apart a bit and discovered the piston no longer moves, but if I push it back manually it moves a tiny bit when spinning it. I also discovered the oil was very black, despite my initial findings. Last thing to do is check the crankcase and maybe attempt to replace the conrod... Thanks for the help


#18

J

jetpackjbd

slomo said:
So you have air, fuel and spark. Still no signs of life. Remaining factor is compression. Time to open her up to check valves and piston/rod.
Click to expand...
Yup. Split conrod.


#19

T

Tinkerer200

And next time post the engine model number so we know what engine we are actually talking about.

Walt Conner


#20

S

slomo

jetpackjbd said:
Yup. Split conrod.
Click to expand...
Another satisfied customer.


#21

J

jetpackjbd

slomo said:
Another satisfied customer.
Click to expand...
Satisfied customer of you, unsatisfied customer of Briggs and Straton.


#22

S

slomo

jetpackjbd said:
Satisfied customer of you, unsatisfied customer of Briggs and Straton.
Click to expand...
Ah, don't go away mad. I've got 5 old Briggs that are perfect. Tip there was old. I love Briggs. Not a fan of their new garbage like you. (y)

You bought the cheapest disposable mower you could find. Notice no commercial guys use the same kind you have? LOL


#23

J

jetpackjbd

slomo said:
Ah, don't go away mad. I've got 5 old Briggs that are perfect. Tip there was old. I love Briggs. Not a fan of their new garbage like you. (y)

You bought the cheapest disposable mower you could find. Notice no commercial guys use the same kind you have? LOL
Click to expand...
Nah, I'm not really upset with B&H. It seems like the old owner didn't care for it very well, and it was 20 years old. We just needed something that could cut our lawn easily for a decent price.

I've tore it apart and found the pieces of the conrod, just bought a new one. Hoping that fixes it, nothing else seems wrong.


Here's it taken apart:
Screenshot 2022-06-11 10.33.49 PM.png

I think the previous owner never did an oil change...
old owner likely never changed oil


#24

S

slomo

Probably used that ultra grade Amsoil 25,000 mile stuff which equates to like 648,000 lawns cut LOL.

Jesus, is that a Diesel engine LOL. Talk about some black tar sludge. Looks like a rear end cover off a Cheby truck.

Keep us posted on the refresh buddy.


#25

J

jetpackjbd

slomo said:
Probably used that ultra grade Amsoil 25,000 mile stuff which equates to like 648,000 lawns cut LOL.

Jesus, is that a Diesel engine LOL. Talk about some black tar sludge. Looks like a rear end cover off a Cheby truck.

Keep us posted on the refresh buddy.
Click to expand...
I wouldn't doubt the previous owner tried running it on half diesel at one point lol.

The conrod should arrive tomorrow, but I can't get the piston out. Any ideas?


#26

B

bertsmobile1

My go to for stuck pistons is grease
pack as much junk. gears , ball bearings whatever as you cam into the engine then fill the remaining space with grease.
The :junk" is just there to take up space & reduce the volume of grease used.
Get the cylinder good & hot so the grease melts down & fill all of the voids and fill the cylinder right up to the top.
Then refit the head , no pushrods so both valves are closed, if they are leaking then lap them first .
Now I have a grease injector which is an old spark plug body with a grease nipple in it.
it goes in loose and grease is pumped in till it oozes out along the threads
The injector is then tightened up
More grease is pumped in till I can not put any more in.
If the piston has not shifted then I pop it in the oven ( BBQ , heat with a big torch etc et etc )
the internal pressure has always popped the piston without any further damage and some of these engines are better than 100 years old


#27

J

jetpackjbd

bertsmobile1 said:
My go to for stuck pistons is grease
pack as much junk. gears , ball bearings whatever as you cam into the engine then fill the remaining space with grease.
The :junk" is just there to take up space & reduce the volume of grease used.
Get the cylinder good & hot so the grease melts down & fill all of the voids and fill the cylinder right up to the top.
Then refit the head , no pushrods so both valves are closed, if they are leaking then lap them first .
Now I have a grease injector which is an old spark plug body with a grease nipple in it.
it goes in loose and grease is pumped in till it oozes out along the threads
The injector is then tightened up
More grease is pumped in till I can not put any more in.
If the piston has not shifted then I pop it in the oven ( BBQ , heat with a big torch etc et etc )
the internal pressure has always popped the piston without any further damage and some of these engines are better than 100 years old
Click to expand...
Thanks for the advice! To clarify though, I'm reusing the piston so I'd like to do as little damage as possible. Excessive heating might not work well. I'll try shoving a ton of oil in it though, hopefully it works. The piston moves but I just can't push it out. I'll try this in a bit


#28

B

bertsmobile1

Full story is a bit different
Piston should come out from the top ( head side ) of the barrel
At the very top of the barrel there will be a ridge of carbon that needs to be removed
They make a really expensive tool called a ridge reamer to remove it without damaging the barrels
Google Ridge Reamer and you should find a mile of you tube videos showing what they look like & how to use them
I usually use a Dremel tool & wire brush to remove it


#29

J

jetpackjbd

bertsmobile1 said:
Full story is a bit different
Piston should come out from the top ( head side ) of the barrel
At the very top of the barrel there will be a ridge of carbon that needs to be removed
They make a really expensive tool called a ridge reamer to remove it without damaging the barrels
Google Ridge Reamer and you should find a mile of you tube videos showing what they look like & how to use them
I usually use a Dremel tool & wire brush to remove it
Click to expand...
Ohhh, is a carbon ridge the carbon buildup on the edges of the top of the cylinder?


#30

B

bertsmobile1

Yes


#31

J

jetpackjbd

bertsmobile1 said:
Yes
Click to expand...
I cleaned that out with some thin wire and poured a bunch of the old oil on the piston. Sure enough, was able to pull it out! Thanks for the advice!


#32

J

jetpackjbd

Currently struggling to remove one of the bolts on the new conrod. I've tried jumping on the torque wrench, hammering it, having two people try at once, spraying silicone lubricant, nothing. Impact drill is charging so I'll try that in a bit, but I'm a bit doubtful that'll work.

If the engine still doesn't work once it's reassembled, I might try throwing a pressure washer engine on. Apparently, someone else has gotten it working. Would be more for fun than practicality though


#33

S

slomo

If you have room, place the rod in the oven. Heat it to 250F and try again.


#34

J

jetpackjbd

slomo said:
If you have room, place the rod in the oven. Heat it to 250F and try again.
Click to expand...
Thanks, didn't see this until after but I got it off with the impact drill. Now I just need to put everything back


#35

J

jetpackjbd

Everything's back together, but still not starting. I suspect it has too much friction, since it's harder to turn than it should be, plus the starter is running slow. Going to try putting some oil directly in the cylinder tomorrow, as that's all I can do for now.

In the mean time, I picked up a junk mower from my local dump's dumpster. Surprisingly, it fired right up on the first try! Needs a new blade and the self-propel system is broken, but I'm fairly confident I can fix those for free. Also pretty gross looking, but it was free.

1655691662125.png
1655691787199.png


#36

J

jetpackjbd

Got the blades sharpened and the 'transmission' adjusted. Works great! It needed a $10 cable but that was it. A total of $10 and a few hours of work for a like-new mower seems worth it. Will be working on the riding mower tomorrow, hope it runs!


#37

J

jetpackjbd

Forgot about this thread, should post an update. The riding mower is still dead, despite everything appearing to work. It gives smoke periodically when starting, but doesn't turn over. I assume either the ignition timing is off or the valves are in need of adjustment. I gave a rough valve adjustment based on what felt right, but without a feeler gauge it's pretty much pointless.
For a while now, I've been trying to remove the flywheel to check if the timing pin is sheared but it just wont budge. Bought the official flywheel puller, no luck.
I'll try buying feeler gauges, but does anyone have any idea for how to get the flywheel off? I'm hesitant to use a torch on it as that might weld it on and make it even worse...


#38

S

slomo

Need to post engine numbers on the rider, serial and model.


#39

S

slomo



#40

B

bertsmobile1

Using a rattle gun on the offical puller usually shifts them
Molten aluminium does not adhere to steel
When filling in holes in aluminium base plates and mower decks I use a piece of steel which just falls off
I did have an old 8 Hp that took a couple of days to shift
Do not heat around the edges pr hit it with a hammer as that can dislodge the magnets inside


#41

J

jetpackjbd

bertsmobile1 said:
Using a rattle gun on the offical puller usually shifts them
Molten aluminium does not adhere to steel
When filling in holes in aluminium base plates and mower decks I use a piece of steel which just falls off
I did have an old 8 Hp that took a couple of days to shift
Do not heat around the edges pr hit it with a hammer as that can dislodge the magnets inside
Click to expand...
Thanks for the reply, what should I use the rattle gun on? The bolts seem to be in enough, I thought I was supposed to be tightening down the nuts on the puller. I don't know if I can really use a drill on a nut in this case 1657852094642.png


#42

J

jetpackjbd

Final update:
I managed to get the flywheel off using a combination of the flywheel puller, a hammer, and a crowbar. The flywheel key was sheared, but I think I originally sheared it in the process of getting it off... I replaced the key and still no luck, it backfires and smokes but that's it. I bought proper feeler gauges and the valve gap was perfect, seemed to have been adjusted recently.
So, after spending around $75 and hours of my time, I've given up. It's not worth it, so I'll be giving it away soon. Today I bought a similar compatible engine for $100, a 12.5HP instead of the original 13HP. Supposedly they're practically identical, just the 13HP's carburetor is tuned a bit different. Both are from around the same year and are in the 28000 series. Almost done swapping the engine, should work fine. The seller ran it in front of me, pretty confident it'll survive a few more years in a mower. Thanks to everyone for the help!


#43

S

slomo

Only one way to find out if the key was sheared or not. New key is only a couple bucks.


#44

J

jetpackjbd

slomo said:
Only one way to find out if the key was sheared or not. New key is only a couple bucks.
Click to expand...
Yeah, I bought a pack of new keys and had no luck. That was what finally made me give in and buy a new motor..


#45

James K

James K

slomo said:
Click to expand...
Gotta love Taryl!


Footer Links 1

Top