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Is This Starter Good

#1

R

Ravenman7

Anyone familiar with starters for B&S Engines,

This is on a Troy Bilt Pony riding mower. The starter will not turn the engine over until the outside temp reaches 85-90 degrees. At tht point it usually starts and runs fine. I have tried adjusting the valve lash with no avail. I can turn the flywheel by hand through the compression so I don't believe that is the problem. The started was removed and tested and though it spins freely when power is applied it does not turn smoothly if turning it manually. It sort of bumps around like maybe a bearing problem. If I spin it by jumping it and hold it upright I can hearing what sounds like a slight grinding or whining noise. Could this starter be the problem? Thanks!


#2

R

Rivets

Starter could be the problem, but I need more info. If you jump the starter while it is installed on the engine, will it start? How old is your battery and what are it‘s cold cranking amps? (CCA stamped on the battery). What are the engine numbers, so we can see what you are talking about? How long has this been going on and what have you done to rectify the problem? When we have the answers to these questions we will have a better idea on advising you as how to proceed.


#3

B

bertsmobile1

They don't turn freely because they are a perminent magnet starter so it goes lumpy as the iron core passes each magnet
Check that the decompression is working by rotating the engine with the rocker cover off and check for one of them ( intake for your engine I think ) opening a tiny amount then closing on the compression stroke.
You can try tigtening the valve lash a bit.
I had these same problem with a customer that has a bad cam.
It would not crank in his cold shed so he would roll it down the hill to his sunny drive.
I would get there a couple of hours latter & it would fire right up.
After a while he dispensed with calling me and just left it in the sun
In the off season I gave the engine a full going over & the cam was bad


#4

B

Bange

My starter burned the armature and had loose magnets.
After repair, it jumped out of my hand when I tested it out of the engine ... it's very fast and strong.
My engine is a B&S 31P777 18,5Hp.


#5

R

Rivets

I know, stupid question. When it jumped out of your hand, did it hit the ground?


#6

B

Bange

No ... it fell on the table ... lucky that he released the cable and hung up.
If not, it would fall on my foot


#7

R

Rivets

If it hit a hard surface, you might have caused internal damage to the starter. The magnets are very easi damaged when you hit them or drop them.


#8

B

Bange

Yes, but mounted on the housing I think it difficult (not impossible), as there are no internal clearances to hit ... it is more likely that the glue will be released.
In my case it was on the bench ... about 10-15 cm high ... it was just a scare, it serves as a warning.


#9

O

olie01

Did they check the armature bearing? if they are worn you will same the same problem.


#10

B

Born2Mow

Ravenman7 said:
Anyone familiar with starters for B&S Engines. This is on a Troy Bilt Pony riding mower. The starter will not turn the engine over until the outside temp reaches 85-90 degrees.
Click to expand...
Ravenman -
Very difficult for a starter to be "temperature dependent", unless 15yo grease on the bearings has oxidized and gotten hard. That's much more of a classic motorcycle issue than lawn mower.

A battery is much more likely to be temperature dependent. But it should be 100% at ~68F and higher, but determining that a battery is "good" is not a simple task.

A look at the de-compression mechanism is probably called for.


#11

R

Ravenman7

Born2Mow said:
Ravenman -
Very difficult for a starter to be "temperature dependent", unless 15yo grease on the bearings has oxidized and gotten hard. That's much more of a classic motorcycle issue than lawn mower.

A battery is much more likely to be temperature dependent. But it should be 100% at ~68F and higher, but determining that a battery is "good" is not a simple task.

A look at the de-compression mechanism is probably called for.
Click to expand...
I have checked the valve lash settings. I tried to start it directly from my farm tractor battery to the frame and the starter. I can turn the crankshaft by hand.


#12

mitchstein443

mitchstein443

I've rebuilt many small engine starters. There's not much too them. and 90% of the 100's I've rebuilt didn't need new parts. All they needed was a good cleaning, greasing and then lasted for years of service.

So here is a simple cheap way to try to fix it.

First, try to turn the engine by hand, it should be hard to turn then jump forward, if it is impossible to turn it's not the starter.
Eliminate it being the battery, use 2 awg or larger (o awg) jumper cables off of your car battery, see if turns, if it does, it's the battery, the solenoid, or bad connection at the cables. most of the time bad connection, wire brush the battery terminals, the cable ends, the starter positive lead, unscrew a starter bolt from the engine, wire bursh it, put it back in (sometime corrosion gets in there).

if you do all that and still not turning, pull the starter.. try to turn the shaft by hand. most likely it will be very hard to turn. if it is:

loosen the two screws that run the length of the starter, but hold the sections together, getting those electrodes back into place is a bugger so don't ket it come apart too far. pull the bottom section about a 1/4 inch from the mid section, soak it with penetrating oil. try to turn the shaft, repeat until the shaft frees up. then turn it some more til it moves freely, then soak the hell out of it and watch all the debri run out. then tighten the two screws back up remount, hook up and bam your starter will work for a while longer. It could last for years, it could last for a week, no way to tell.. in the mentime figure on replacing the starter asap..

Thats a quick cheap fix that works more times then not for older starters tht have been sitting around.. I just did one yesterday on a 1972 kohler opposed twin, that I had doe the samething to 5 years ago.. It's still the original starter..


#13

mitchstein443

mitchstein443

mitchstein443 said:
I've rebuilt many small engine starters. There's not much too them. and 90% of the 100's I've rebuilt didn't need new parts. All they needed was a good cleaning, greasing and then lasted for years of service.

So here is a simple cheap way to try to fix it.

First, try to turn the engine by hand, it should be hard to turn then jump forward, if it is impossible to turn it's not the starter.
Eliminate it being the battery, use 2 awg or larger (o awg) jumper cables off of your car battery, see if turns, if it does, it's the battery, the solenoid, or bad connection at the cables. most of the time bad connection, wire brush the battery terminals, the cable ends, the starter positive lead, unscrew a starter bolt from the engine, wire bursh it, put it back in (sometime corrosion gets in there).

if you do all that and still not turning, pull the starter.. try to turn the shaft by hand. most likely it will be very hard to turn. if it is:

loosen the two screws that run the length of the starter, but hold the sections together, getting those electrodes back into place is a bugger so don't ket it come apart too far. pull the bottom section about a 1/4 inch from the mid section, soak it with penetrating oil. try to turn the shaft, repeat until the shaft frees up. then turn it some more til it moves freely, then soak the hell out of it and watch all the debri run out. then tighten the two screws back up remount, hook up and bam your starter will work for a while longer. It could last for years, it could last for a week, no way to tell.. in the mentime figure on replacing the starter asap..

Thats a quick cheap fix that works more times then not for older starters tht have been sitting around.. I just did one yesterday on a 1972 kohler opposed twin, that I had doe the samething to 5 years ago.. It's still the original starter..
Click to expand...
If your comfortable with putting the electrodes back in proper place you can just remove the two screws, seperate the thirds (top body(magnet) and bottom) use carb or brake clean to clean up the "bearing" areas, dry well and relube with wheel bearing grease or white lithium grease. I like to add just a spot of silicon oil to the grease, foud it lasts more winters of storage that way and spins faster in colder weather. (like -40c up in my alberta canada home).


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