Installing 787 Top End

[jennie2376]

Is there an installation guide for the Seadoo 787 engine top end? if not what are the torque specs, rave value adjustments, and what side does the intake holes on the piston face?
Thanks,

Jennie2376

[ashpapi]

Re: Installing 787 Top End

I know it's confusing, but the best man in this area says the arrow on top of piston ALWAYS goes to the exhaust. The intake hole is opposite side, but this motor has intake and exhaust on same side so hole is taken out of play? It's always worked for me, I have done quite a few. specs should be readily available, if not, I will send them from the manual

[dsolie]

Re: Installing 787 Top End

Arrow towards exhaust, always....

Manuals available for free at seadoomanuals.net

[ashpapi]

Re: Installing 787 Top End

I can't tell you the number of times I have started to do an engine and had to do a "mock" (just line up all parts) rebuild so I got the arrow to the exhaust. I think it's wise to really look ahead & do this procedure to save time of re-aligning pistons.

[str8g]

Re: Installing 787 Top End

Just throwing this out there. if your new top end is the same piston size as the one you are replacing this shouldn't be of concern but if the new top end is a larger bore than the one you are replacing, your rave valves may need to be relieved or ground to match up with the larger piston size. I am not super knowledgable on this topic but its been explained to me that if the new top end is a larger bore or piston size that this makes the piston and rings closer to the rave guillotines, if not initally but after wearing in for a while. they can then make contact with the piston and rings causing damage and premature rebuilding of the topend again. Just throwing this out there if that has never been explained to you. You hadn't mentioned the nature of your rebuild whether the new top end swap, the same size, or if your cylinders were bored to a larger size.