"Head Job"

[cameron da river rat]

can you re-cut the squish area on a head. the jet ski i sold my friend (94spx bored .020/.50 over) has increased it's compression since it was bored, i have not checked the squish gap but suspected that was the culprit to the 180psi cold and 175psi warm cranking compression.

and yes that was useing sea doo's largest base gasket. no i did not want to spend the time dropping cc by cc of oil into the cylinder to do an actual compression ratio check, so i have no idea what it is, i just told him to run 93oct.

is this compression stock??? my clymers manual shows the 657 (not X) to be/have more compression than the 587, 717, and the 787. so far it's had two summers of "no problems yet" riding and no sounds of detonation comeing from the engine. [img]graemlins/spit.gif[/img]

[Bryan Glynn]

When you install oversize pistons you must open the squish land or you get the raised compression due to a shelf on the outer edge.

No we don't do one-off shop work, sorry.

I don't advise running the ski as it is, I would advise you to have him send it to Watercraftmagic or PPG and have them cut the head.