Is This Starter Good

[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!

 

[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.

 

[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

 

[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.

 

[Rivets]

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

 

[Bange]

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

 

[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.

 

[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.

 

[olie01]

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

 

[Born2Mow]

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.

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.