Small Engines (Lawn Mowers, etc.): B&S 10hp OHV - Bent pushrods, briggs and stratton, valve clearance

Question
I have a yard chipper with a B&S 10hp model 204412,type 0276E1, code 031110YD.purchased 3-30-04. Runs great but for some reason it has bent push rods more than once. Total run time on engine is less than 80 hrs Oil is changed once per year. Will run for about 10-12hrs. With no problem,then with no load, stops due to bent push rod. Very clean burn on plug. No visible carbon on valve stems. Good compression. Valves adjusted to spec.004-.006 Help!

Answer
Odd for push rods to bend mulitiple times.  Have you checked the rocker arms to see if they are wore, causing the push rods to be misaligned?  Are the rocker arm screws bent?

Have you checked the valve clearance at the 5 hour running time?

Are you replacing with Briggs and Stratton push rods or aftermarket pushrods?

Eric