Small Engines (Lawn Mowers, etc.): 12hp Briggs and Stratton, TIGHT WHEN WARM?, briggs and stratton, rod bearings

Question
hi there
ive a problem with my 12hp briggs and stratton engine, it will start fine when cold, but when its warm it is really tight? is this the valve clearances? if so what should they be?
it is a vertical shaft L head without the warm cam adjuster thing! any help would be good!!

Answer
If it was valve clearance it would effect starting cold too.  You say tight.  Do you mean sleazing?  If that is the case the best thing to do is remove the engine and do a physical teardown of the engine and inspect main bearings, rod bearings and cylinder condition.  

Valve clearance is set by the manufacturer and the best place to find it is the engine manufacturers web sight.

Hope this information helps.