Thanks, a valve seat issue would make sense. I went and checked this am and #2 cyl is dead. Removed the valve cover and #2 is open about 1/8". Might make for an interesting disassembly video. I'll be pulling the head later this week.
Craig N886MJ > On 12/12/2022 7:21 AM CST Mark Jones <flyk...@gmail.com> wrote: > > > Craig that sure sounds like a dropped valve seat to me. I had the same thing > happen on my first engine. > > Mark Jones > Oldsmar, Fl > > N771MJ “WunderBird” > www.flykr2s.com > flyk...@gmail.com > > > > > On Dec 11, 2022, at 9:24 PM, Craig Williams <cr...@kr2seafury.com> wrote: > > > > So today I was running the engine to test a new tach and something broke. > > Everything was normal and WAM BAM the right side AFR went off scale lean. > > Now engine barely runs. After much contemplation I think maybe an intake > > valve spring broke or I have an intake valve stuck open causing loss of all > > vacuum on that side. I pulled apart the intake on that side and it all > > looked fine. The plugs were bright white like an excessively lean mixture. > > The left side plugs look normal. Now it barely runs like a one cylinder > > engine which I think would make since because the common intake with a > > massive leak would screw up the left side vacuum too. My thought is to > > unbolt the intake off the top of the head and use my palm to cover it and > > see if there's any vacuum at all. That might be a clue. Anyone seen this > > or have any other idea to troubleshoot this. When Roy rebuilt my heads we > > tested all the springs and they met the GM specs but I have no idea how > > many miles might be on those things. > > BTW on a side not I had new sealed Power spring but they tested way above > > the specs so I elected not to install them. > > > > Thank the lord this happened on the ground. Unlike my last adventure. > > > > Craig > > N886MJ > > -- > > KRnet mailing list > > KRnet@list.krnet.org > > https://list.krnet.org/mailman/listinfo/krnet -- KRnet mailing list KRnet@list.krnet.org https://list.krnet.org/mailman/listinfo/krnet