Small Engines (Lawn Mowers, etc.): 303477 16hp v-twin vanguard B&S, valve service, frame flex

Question
My Engine was back firing through the carb. When I went to check the valve lash I found the exhaust valve push rod bent. I have one ordered it is aluminum. I have set the intake at .005 and the exhaust at .006 now? I was wondering one if those setting are good. The book calls for .004-.006 on both intake and exhaust. and two what cause should I look for that bent the push rod? Thanks for the help Wayne

Answer
Usually there are a number of things that have to happen at the same time to bend a push rod.  Engine age, mower frame flex inducing addition vibration, weaking engine frame mounting platform, and general engine wear.  We do find bent push rods once in a while.

The link below describes the valve service procedure:

http://www.briggsandstratton.com/engines/support/frequently-asked-questions/Serv

The service manual states .004-.006 of an inch for both valves.  Pretty common OHV gap spec.

What is the engine type number?  Are there push rod guides in your engine?

Eric