Super Jet Looking for thin base gasket...

[NISMOtuner]

I just finish putting my ADA head with 35cc domes on my ski and checked compression before the swap (which was 130 on both cylinders exactly the same) then I put my new head on and it reads 160 psi on both cylinder exactly the same. I did some researching and it seems that the most likely reason would be that when the last owner rebuilt the motor, they possibly used an aftermarket gasket that is thicker. To remedy this I am looking for a thinner than stock base gasket (bc If it fixes my issue then I wouldn't mind having the extra compression anyway). Can someone point me in the right direction? I've found plenty of factory base gaskets?

Also I found this ad but I'm not sure of brand so didn't want to just jump.

http://www.amazon.com/CYLINDER-BLASTER-1994-2005-WATERCRAFT-REPLACEMENT/dp/B00JLQG3KK

 

[blaster800]

LPW had some '' JR. '' screen name , give him a shout

 

[kurtwolff]

You need to make sure your squish is correct if you go thinner. I would pull your current base gasket and measure before getting too far into it...

 

[amitchell]

How do you know your compression gauge is correct?

Like @kurtwolff said you have to check your squish before you change your base gasket.

 

[JetManiac]

Agree with their advice. Check squish before changing anything! Also you have 701/35cc domes for sure and not 760/35cc by accident?

We have thinner and thicker custom base gaskets if needed.

 

[NISMOtuner]

I'm pretty sure I have 701 35cc domes. They were brand new and labeled on the packaging. And I just checked my squish this morning and got .43 front and .41 rear. Isn't this what the squish is? So shouldn't it be thinner since I'm using the ADA head?

 

[NISMOtuner]

I'm assuming my compression gauge is correct just bc I use it quite regularly in the shop. I build cars as a side job so it gets regular use.

 

[amitchell]

0.43mm?

0.043in?

If it is 0.043in leave it alone, thats a good squish clearance. Now if this is the case your compression gauge reads low or your compression is low, check it with another gauge and report back.

 

[JetManiac]

Have you considered that you might just have a tired motor?
130 is low for a stock motor and now you have 30lbs. With the ada head but compression is low because you started so low.

 

[Balduccimoto]

Did you check while the engine is cold? Just want to make sure you are on the correct path:

Ride the ski and get the motor warm. Shut it off and do a compression check with the throttle wide open. If it's still low.. Squirt some oil inside there and give it a minute so it runs around the outside circumference of the piston. The idea is to saturate the cylinder wall and piston rings. If there is wear inside, whether it's worn piston rings or heavily scored cylinder wall; you will end up seeing a spike in compression after adding the oil. At that point it's time to tear down and inspect everything.

Definately don't touch the base gasket. Your squish clearance is perfect. If you put a thinner base gasket there then you will end up reducing the squish band and with the effects of doing that, you will create detonation.

 

[NISMOtuner]

Ok I'll recheck because the engine was cold when I checked it. Didn't think one bit about warming it up.