Super Jet 125psi??? youve gotta be kidding me

[ProSouth]

Ingesting**.

 

[River Rat]

http://www.youtube.com/watch?v=vB3IkQSHiAQ heres a video of the clapper ski i have

That's what my bed sounds like at night , i guess my bed is clapped out :/

 

[ProSouth]

Sounds like you're clapped out...

 

[superjetguy]

ill figure that all out after i rebuild

 

[ProSouth]

Good luck, hope you get it all worked out

 

[Little Trumps Super Jet]

Wow, a call to the ski clinic couldn't hurt to go, really? Maybe theyl help you out

 

[superjetguy]

So anyone who was wondering, I rebuilt my ski myself and I have 215psi in each hole with the same compression tester.. All I can say is wow. It's a completely new ski. Also found out the orings on the head were shot so it was getting water into the cylinders too.

 

[JetManiac]

cool. why do you have 760 domes on a 701 motor?

 

[Nuklear6]

Hmmm it's ported and you were told to use stock 701 pistons?
I'd be measuring that bore and ring gap, ASAP.

A few years ago I bought a ported BB topend with new pistons from a board member. It ran okay but had low compression (120ish) even though I was using domes that should have gotten me nearly 200 psi. Turns out that the bore was big enough to actually need 85.00mm pistons, not the 84.00mm that were shipped with it.

That actually ran?!?!?!? Lol shows that piston to cylinder wall clearance can go a bit further out of the .008 max service interval we engines builders preach...

 

[Nuklear6]

Also keep in mind when talking piston to cylinder wall clearances and service intervals. if you correctly measure a piston it has to be done approx 1/2" below and perpendicular to the wrist pin. Pistons are NOT a perfect cylinder. They are purposely smaller at the top where pistons temp is much greater (therefore expansion is greater when running).

To the OP, hopefully this isnt the case but if in a short period of time you experience your head o rings giving up again. you may want to at least check the deck surface for square if not just have someone with a machine take a slight cut to assure it is perfect for the o rings to seal.

 

[superjetguy]

I'm running 760 domes because I have a r&d head and was planning on buying 701 domes but you can't find them anywhere and I figure it works fine.

 

[Zero Client]

Sound like it's working fine, just understand the 701 is 81mm and the 760 is 84mm. Your domes are bigger slightly. You are making a very slight mushroom cap up top around the squish band.