Zekester

Forgive me if this is something obvious,

I've got a 22' 1987 Donzi with a 502 in it...I've got a bad knock and am pulling engine out....one theory was that i got water back through the exhaust manifolds (stock) and water locked the engine. I have stock manifolds, stock risers and down pipes that go back and down to exhaust outlets in the transom with flappers on the pipes...

Can I get cooling water backflowing from the exhaust and back into the engine? the 502 isn't stock, could the cam have too much overlap and suck water back?

sutphen 30

short answer,,yes

im MartinB

I've had hydrolock 3 times in over 30 years of boating. All 3 times I removed the spark plugs to spin the engine and was fortunate there was no damage. 2 of the 3 times the engine was revving and then shut off... the other time I never figured out what happened but it never happened again with lots of boating. Reversion has been an issue a couple times but just required less water through the exhaust and also lengthening the inner dry portion of the exhaust. Reversion shows up in your oil pretty quickly and can make for weak idle. I've never had reversion cause any sort of hydro lock.