[z440snopro_23]

i have a 1999 z440 sno pro and i think i have some piston and rings problems. does anyone know what the compression be.

 

[?????80]

Im not sure about the sno-pros with the racing heads, or even the trrail heads even , but most machins need atleast 110-120 psi to run , idealy 130 -140 are prefered, but even with 120 or maybe even 110 doest mnea ur engine is gone.What numbers are u running? My 580 blew the head o-rings and droped to 75 on the right and 100 on the clutch side, she managed to run after a few hundred pulls ,s still had her snap , but was burining alot of antifreeze.Hope this helps.

 

[sysanalyst--off]

On a ZR440 Sno-Pro, expect around 135-140psi hot with a couple of good pulls of the starter cord. I measured mine over the past weekend before I drove it the first time to establish a baseline. You are using premium 93 octane fuel? What do the plugs look like?

 

[KevinS]

<div class='quotetop'>QUOTE (sysanalyst @ Jan 30 2007, 09:42 PM) <{POST_SNAPBACK}></div>

On a ZR440 Sno-Pro, expect around 135-140psi hot with a couple of good pulls of the starter cord. I measured mine over the past weekend before I drove it the first time to establish a baseline. You are using premium 93 octane fuel? What do the plugs look like?[/b]

Wrong sled. The Z440 is fan cooled. I imagine compression should probably be in the 120s. 135-140 is into premium fuel only range.

It is more important for all the cylinders to be all the same vs looking at what the number actually is. A lot of gauges read differently. Usually no 2 gauges are alike. You don't want a difference of more than 10%.