Just had some warranty work done on my engine and was told the valve lash setting is different than the 35's. This was per the Briggs tech service rep. (Briggs direct, not a dealer)

The 35's have always been .004-.006, this is also what the engine manual for my 37 says. When I picked it up my service ticket said something like .005-.007 intake and something like .006-.009 for the exhaust valves. Has anyone else heard of such?

For the record, I've always experienced the best all around performance at .004" (both valves), Al Hodges recommended .003" over the phone not long ago, and I was considering trying that the next time I checked and adjusted them.

Yep .005 intake .008 exhaust. for the 37's

I wonder why that is. Honestly with the valves set at that kind of lash, this engine feels lazy as hell. My powerhead just got the "updated" Briggs heads put on it after having valve sealing issues with the first set. My understanding was the heads were identical with the only difference being the new ones have an actual factory valve job. No different valve or seat material and everything is the same size. Any good reason for the change in lash spec? I'm probably going to reset them to .004 where they have always ran the best if nobody can really give a good reason not to.

I was told it allows for sufficient lash when the valve heats up and expands sufficient lash is maintained. As to why only on the 37's... Who knows man. I set all my stock cam motors .004 intakes and .006 Exhaust on all motors.. Aftermarket cams with different valves Ill set around .004.

I understand exhaust valve growth due to heat etc, but I just wonder why this is just now being changed lol. The 35's exhaust valves have ran hotter than the intakes for years