Hello! I just purchased a 2002 Honda CBR 600 F4i and I was going to compression test it but I can't seem to find what it should read out to. Also a general question: what should the normal riding temperature of this bike that displays on the gauge? Thanks for any help, its greatly appreciated!

 

you need to test compression while the engine is warm and with the throttle open, and all other spark plugs removed. it's a bit of a pain on a sport bike.

the factory service manual says 178lbs compression is factory spec

... but i'd accept any reasonably high compression where all of the cylinders are even. if there's a problem usually only one or two cylinders flunk, not all of them.

temperature? depending on conditions, anywhere from 80c to 110c is normal. (aka 175f to 230f). these bikes run really hot while moving slowly, so until the warning light is on, and as long as your fan works, no need to be concerned.

 

Welcome to the forum mar.

 

anything over 160 on compression is generally acceptable. Ive never done one with the engine warm, but definitely need the throttle wide open.
tempt should stay around 180 while on the move, it'll obviously climb when you're in stop and go traffic, fan should kick on around 220.

 

Thank you to everyone for the quick responses. This is my first CBR, I have always heard they are the best 600's. I can't wait to get on the road this summer.

 

You don't live somewhere warm obviously. OP- the temp depends on your surroundings. When its 115* outside I can easily stay at 200* going down the freeway. When its cold as hell it'll stay at 170* doing the same drive.

 

it rarely gets that hot here in indiana, and when it does my *** is planted on the couch enjoying the AC

 

I am in the middle of a valve check on my 02 f4i and decided to check my compression real quick, bike was not warm as i have it all ripped apart.. but did not know about the throttle wide open part?

anyway i had numbers like 170lbs dry / 180lbs wet - all cylinders were very similar or consistant with each another. I gather thats more what its about.

 

Throttle wide open means there is no vaccum in the intake, the cylinder can get as much air as possible giving correct compression numbers. Closed throttle can mean lower compression figures. Yes, having them all about the same is what really matters in the end. I'd be happy with your results.