how much compression?

[jas250r]

my new ct 350 pv has about 160. i checked after i have ran around a gallon of gas threw it. it's just the basic pv kit. no higher comp dome. has just basic clean up port job. where should it be around? runs good. when i do the first topend i will have it ported some more.

[Honda 250r 001]

maybe a little low. 160 is stock if that helps you any. but i also heard that running lower comp on a big bore helps her last longer.

[jas250r]

i tried it again today but warmed the motor up before, tried 3 different gauges, same reading, called ct. allen said to take head off and see if i toasted the rings, should be around 200. i was kicking about 1o times. he said try about 25 to 30 see if it still goes up some. i will try again tommorrow

[jas250r]

screw it went back did 25 and got 180. actron was what i used for 2 and the other was a cheap harber freight deal. i have used the actron with my stock bore and seemed correct. i might try another, or buy a better one?

[LONG-ROD]

when we did my bro's 310 allen sent the wrong o rings. WE started it and it ran for a few min, then noticed a little fluid runing down the cylinder. put new ones in when we got them and was fine. Did your o rings look like they fit right when installed. and did you tourqe the head down like it should?

[Honda 250r 001]

there is no certain ammount of kicks you have to get a accurate compresssion reading. you kick until it stops going up. and you keep the throttle open.

[jas250r]

yeah o-rings fit perfect. i'll do it agian. it looked like it was still moving up a little at a time, real slow

[Aceman]

25-30 kicks:huh

I usually get mine in about 8 or so. Maybe you should have your girlfriend come out and show you how to kick it!:devil: Even better, take your Scooby slippers off next time.


:blah:

[derby]

My ct350 always felt like it had more compression than any other bike that I had ever kicked. But no matter how many times I checked hot or cold it stayed around 180lbs. My stock cylinder 250r with no porting or head mods(cr250 gasket would read 195lbs). I ran the ct350 down until about 160lbs of compression before I rebuilt it. It does not matter how many times you kick the bike it will reach a peak pressure then it will read no more. I assume the difference in compression is of course attributed to the head volume, but also have heard that porting has something to do with it. But I guess I dont understand how porting effects compression.

[All250R]

170 +/- 15 is the factory rating for stock cylinder compression just as an fyi. If you think it should be making more compression make sure you're holding the throttle wide open. That helps it suck the volume it needs to get a peak compression reading.

Porting effects timing by determining when the rings seal off the cylinder. Exhaust ports are often raised when porting and will influence how much actual fluid is compressed in the engine - so will pipe effects. :blah: