95 speedster new engine problem

[nic32]

Hey guys ! I love this forum !!

Recently, my starboard engine have failed and I rebuild it. The engine runs fine outside the water so last Sunday I bring this boat in the water to take test.

It was new so I running about 3-4 k rpm and suddenly the engine went down at 1,5 k whatever full throttle or not. So I take it I go home to check the problem.

At home, I started the engine and the engine runs fine. I don't know what is the problem.

Notice that I have a little water leak on the exhaust coupler where the second part of the exhaust get plugged in. Can this leak can cause the engine problem.

Second Notice, I have installed the thickest base gasket to help my motor for not to big compression and I check the compression and It is at 120 psi when the port engine have 135 psi.

Thanks for all response and sorry for my bad english

 

[nic32]

I forget to mention that I have twin 657x engine !!

 

[seadooya]

low compression, hurts motors. Need to do the "squish" test.

 

[Dr Honda]

120 psi isn't enough for a SeaDoo engine. When you built that engine, you should have checked it properly, and set the base gasket. You want to see about 145 psi on a fresh rebuild (Zero hours)

Any exhaust leak can cause issues, so check it over, and fix them.