compression

[vtr1000bart]

[attachmentid=1466][attachmentid=1467]hey

just been checking out a cbr250 (import)

the compression measurements across the cyclinders are;
1. 180 PSI
2. 180 PSI
3. 155 PSI <----- <_<
4. 180 PSI

should i be worried about the low reading on cyclinder 3? or is it within the "range"

oh and dirt has entered the airbox at some stage.

this is from a mechanics report.

any thoughts would be apprciated (related to this post)

cheers

[shrike]

I&#39;d be worried, but then I&#39;m anal.

Do a second test, to be sure. I remember taking my car in to get a compression check and it came back with one low reading. Took it to my regular mechanic who checked it and it came back normal and even across the board. He said it could&#39;ve been a bit of carbon blocking a valve from fully sealing or something.

25 PSI isn&#39;t much in the scheme of things, but if it starts getting to 30... 40... 50... etc, well...

[Jonchilds]

If the bike is running fine, and smoothly - then I&#39;d not be too worried. If you&#39;re getting it missfire regularly, then it&#39;d be something to get checked out.

Most you&#39;re going to get from a 15% decompression in one cylinder is a slight loss of performance, and either some blow-by, or valve leakage. Neither is particularly urgent to fix, and can usually wait until the next time the head is off (atleast that&#39;s what I do with my cars).

[skitz tc]

id take all the advise from above and do a second test but when i did a compression test on my car it was out by less than that and i had to fet the head skmmed off and a new seal kit to stop it from leaking a bit which aint a major problem it aint something u want but ya can survive with it. i dont know much bout bike engines im not sure if there the same kinda things as cars im guessing not .