Honda CBR 600RR Forum banner

1 - 2 of 2 Posts

136 Posts
Discussion Starter #1
Hi All (I think this is the appropriate section?)

My bike had some overheating issues last season due to some issues with the coolant system (all taken care of now). I haven't had a chance to run the bike through its paces since the season ended so I decided to run a compression test to see if everything is ok inside.

Rented a tester from O'Reilly's (had to buy an adapter for our tiny threads) and my numbers were as follows

Cyl 1: 150 psi
Cyl 2: 150 psi
Cyl 3: 149 psi
Cyl 4: 146 psi

(2006 CBR600RR, basically stock motor, unknown miles)

Now my question is this, are these numbers ok? I've read different things online, like I should be around the 150psi mark, but the service manual says 178 psi. However I've also seen that the number could be lower depending on the tester itself and that I can't be 100% unless I did a leak down test or something of that sort.

I know that you want each cylinder to be within 5% of the others (7.5psi in my case) and I at least have consistency across the board.

Any reason for concern or should I be ok?


33 Posts
You sort of laid it to rest yourself.
Does it burn oil? If not or minor - Don't worry about it.
Last time valve clearance checked? Have they gotten tighter/changed?
Any coolant loss or boils?

The cylinders are practically identical. -Without having to refill oil or coolant due to burning or boiling. And with the knowledge that the valves are within spec-, I would give it the green light :)

Next step, if you feel needed, would be to do a leak down test. This is to better pin point where the leak/hiss of air is escaping. Best done with the valve cover off, throttle bodies WOT and oil refill cap off. Listen at all three areas for hissing noise! Some leak is expected, but excessive leaks are very noticeable (they differ in sound from the other 3 cylinders)
1 - 2 of 2 Posts