CBR250RR compression tester

**vtec** · 2nd October 2006, 21:27

Hi all.

I've been trying to find a compression tester that will fit the CBR250RR spark plug holes. I think it needs a 10mm connection to fit. Does anyone have one that I could borrow, or point me in the right direction to buy one.

I've felt for a while now that the bike isn't quite running at 100%, and it doesn't idle like it used to, and it misses a lot down low. I've just stripped the bike down to check the valve clearances (all still within operating limits). Checked the A/F ratio screws all fine. Will strip and clean the carbs to be sure. So the last thing to check is the compression.

Another thing it could be is electronic. Either leads or rectifier, or something like that. It's only at low rpm though thankfully, and it does seem to be intermittent, although nearly all the time now it will miss at low rpm. Not good, cause I'm going to be selling up soon.

**Delirium** · 3rd October 2006, 12:31

check the spark plug gaps/clearances aswell. sounds like you know what your doing though. let us know as you go on bro.

**k14** · 3rd October 2006, 12:59

check the diaphrams. when i had my mc22 and pulled the carbs apart i put didnt seat one of the vaccum diaphrams in properly and it was idling like a piece of crap. pulled them back apart and it fixed it instantly.

**HDTboy** · 3rd October 2006, 13:29

Courier me the carbs

**vtec** · 3rd October 2006, 18:19

You're not touching my carbs Gav :P You might rejet them or something.

I've already got a set of yours that I'm not going to use, cause the are jetted for a freer breathing setup.

With regard to the spark plug clearances. I haven't checked them, but they aren't all that old to be quite honest. I've done tonnes of maintenance on this bike, and everything is up to scratch. I think it's either compression issues or electronic, but I'll rebuild the carbs aswell to be sure.

**Delirium** · 3rd October 2006, 21:10

Originally Posted by vtec

With regard to the spark plug clearances. I haven't checked them, but they aren't all that old to be quite honest. I've done tonnes of maintenance on this bike, and everything is up to scratch. I think it's either compression issues or electronic, but I'll rebuild the carbs aswell to be sure.

doesnt matter if they are brand new out of the box or not. my mate bought some high performance plugs for his car a while ago that cost about $40 each or something. anyway we put them in and it was idleing really shit, like it had some aggressive cams in it or something. so we pulled them out again and one of hte plugs, the gap was way to small for some reason (might have knocked it), so we reset that and it was all a okay!