Convert Squish to Compression.

[Michael73]

Hey Gang,

My 800 seadoo engine again!! Its getting there.. Well, the squish with a .4mm base gasket is 1.6mm on the rear pto cylinder and 1.5 to 1.55 on the front mag cylinder, I understand it is desirable to have a tad less compression in the rear pto cylinder.

With there being between .05 and .1mm squish difference between cylinders, how much actual compression figure difference will there be, ie 5lbs? even noticable? It still got the stock head and .5mm pistons. Otherwise stock. :D

Also I'm finding it very hard getting an accurate squish measurment, I cant buy any 2.0mm solder in my city, only 1mm. So what I have been doing is folding 1mm back on itself and trying to get it to stand up in the cylinder.

Do you have 2mm over there, or is there another method?

[ November 15, 2002, 05:54 AM: Message edited by: Michael73 ]

[Bill O'Neal]

Find an electrical supply store, they sell solder in .029,.060, .090 thicknesses. Get soft core solder.

You will never get the exact same measurment, due to piston rocking in the bore. I take the test three times and average them.
You will not get a different compression ratio in the two clyinders because of a slight difference in your measurments.

[cameron da river rat]

you could stick a piece of solder on both sides of the piston??????..................i went to a local radiator repair shop and got some solder, they asked what it was for and when trying to explain to them they just said here take some.............. [img]tongue.gif[/img]