Running no base gasket, 650/750 engines...

[Cannibal]

Hey, just something I ran across. Didn't know if anyone was running such a setup or not.

Since there is no gasket, maybe pressure test it periodically, or at least at the start of every season???

 

[Waternut]

maybe pressure test it periodically, or at least at the start of every season???

I think that's good advice no matter what... Seems like so many people think of boats and jetski's like a car. Drive it until there's a problem and then fix it except that boats and jetski's are driven at 100% a lot of the time where your car is built more reliably and driven at 20-30% most of the time. A minute or two for a visual inspection every month or two will often show the little issues that are creaping up.

I ran my kawi a full season and pressure checked it because I was bored. It didn't feel any different than before but it did have a small leak that was causing roughly 1psi loss per minute.

Half a season on my SJ and one of the case bolts had backed itself out and was pinned against the hull.

 

[Crab]

fyi fella's, you still need to maintain proper squish, approx. .040 . My exhaust ports are ported a bit so this was a way to get back some low end. Even .010 alters the blowdown and port timings, I consulted 2 engine builders on my setup before I went ahead with it. My cylinder has been on for 2+ seasons and the only issues have been maintaining the seal at the head gasket.