Yardman engine won't turn when hot

[kansharma]

Yardman riding mower with Briggs & Straton - engine doesn't turn when hot

My Yardman riding mower has a Briggs & Straton engine that does not turn when hot. The engine starts and runs great when cold. However, once the engine is hot and if I turn it off then I have to wait for about an hour before it cools down and can be restarted. When trying to start the engine while it is hot I can hear the engine trying to turn over but it is usually about half or one turn and then nothing. I can then release the key, try again and get a single turn out of it but not get it to turn over enough times for the engine to restart. I do believe that if the engine were to crank properly it will start.

I am thinking that it could be the starter motor but not sure where to start. Help please.

 

[KennyV]

WELCOME to LMF...
This is a problem that comes up often...
One of the recent posts covering this is :http://www.lawnmowerforum.com/small...ing-mower-barely-turns-once-doesnt-start.html
There are a few answers from a couple of our Best posters.
That thread also links a youtube video clip from one of my favorite youtube folks... ( HOW TO ADJUST VALVES) FIX HARD TO START Lawn Tractor with OHV Briggs Engine- MUST SEE- Part 2/2 - YouTube
Post back with what you find... :smile:KennyV

 

[DaveTN]

Re: Yardman riding mower with Briggs & Straton - engine doesn't turn when hot

My Yardman riding mower has a Briggs & Straton engine that does not turn when hot. The engine starts and runs great when cold. However, once the engine is hot and if I turn it off then I have to wait for about an hour before it cools down and can be restarted. When trying to start the engine while it is hot I can hear the engine trying to turn over but it is usually about half or one turn and then nothing. I can then release the key, try again and get a single turn out of it but not get it to turn over enough times for the engine to restart. I do believe that if the engine were to crank properly it will start.

I am thinking that it could be the starter motor but not sure where to start. Help please.

More than likely the trouble is in the top bushing that the crankshaft goes through at the flywheel. What happens is the bushing starves for oil and heats up due to deposits on the crankshaft from the bushing. Metal rubbing on metal and heats up~~~ Cold metal contracts and you have clearance. Let it get hot and it seizes up due to metal expansion taking up the clearance. Let it cool down and you're back in business but not for long. Bad news is you're looking at a total engine disassembly just to get to the top crankshaft bushing to replace it. Hope someone else can find an easier solution. Dave