300/440/550 550 compresion question

[ckjetski]

my freind is looking in to buyng a stock 550 sx. And he is wondering what the psi range it should be in?

thanks

 

[Big Kahuna]

91-94 550sx (reed motor) ran an average of 165-170psi for cranking compression.

 

[ckjetski]

what about 89?

 

[shorty]

That's way too low. Needs a rebuild. Good luck.

 

[32vickie]

what about 89?

I hope he was talking about a 1989 motor and not 89 PSI

 

[ger87410]

I have an '89. What's the compression supposed to be?

 

[SQUARE JOEL!!!]

Clymer's says for 85-on 550 should be 78-112

 

[ckjetski]

haha ya my bad i meant an 1989 550.

 

[Big Kahuna]

piston port motors ran about 135-140 psi.

 

[EightySeven550]

My stock ski was running great at 125 125.
My uncles stock somehow ran 145 145.
Both 1985 550 Piston Port skis.

 

[Mort]

550 compression

Just measured mine the other day 135 per cyl.

Matt