Bent Exhaust Valve Pushrod

[Spaceman22066]

I have a cyclone rake leaf vacuum with a 9 hp B&S Vanguard engine that suddenly stopped running and then would not turn over using the pull cord. I noticed it had been backfiring through the muffler when starting or when the throttle was reduced so I suspected the values needed adjustment. But when I pulled off the cover plate I noticed that the exhaust valve pushrod was separated from the rocker arm and upon further inspection I found that the pushrod was slightly bent. Also, using a magnet wand tool found a small amount of very fine metal shavings down near the bottom of the pushrod coupling on the cam. Before I install the new pushrod, has anyone had a similar experience? I am wondering if this was just a loose valve problem or I need to look at the cam or compression release.

 

[mechanic mark]

Absolutely a loose valve problem.
Find Your Briggs & Stratton Manual: Small Engines Enter your model & type numbers and you'll have manual & parts list for your engine. After installing new pushrod adjust valves to specs. per manual, change oil & filter, run engine ten minutes, recheck oil on dipstick for metal, change oil & filter again if necessary, you should be good to go. Valves need to be checked & adjusted every 250 hours, see what your manual says. Let us know how it goes, thanks.


















Absolutely a loose valve problem.

 

[motoman]

Spaceman, Soft cam lobes are apparently a widespread problem, but would , I think, produce powder as they wear and you probably would not notice. Shavings ? The drop out of the pushrod caused by bending and shortened engagement. A lot of opinions are that the valve momentarily hangs up in the guide due to deposits ? or ? seizure. The lifter in my 'ole Intek did not wear at all as it destroyed the cam lobe.