2008 CRF150R Valve Adjustment help needed

2008 CRF150R; I have 7 hours on my bike and have lost a lot of power. From the talk on the TT site I imagine my valves have tightened up. My problem is that I am in Okinawa, Japan and my manual is in Japanese. I ordered an American Manual, but don't want to wait to ride. Is there a detailed "HOW TO" somewhere in this site or on the net that I can follow to adjust the valves and, what special tools do I need to buy? ie certain size feeler guages, etc. I already changed my filter and engine/tranny oil with MA 10W-40/30 if it matters.

get some feeler guages that range from .001-.015 inches. and a torque wrench. If you are experiancing a loss in power it may be your rings that are worn. the valves usually cause it to be hard to start. there is a post in here on a crf250 valve adjustment that is very similar just do a search. There should not be power loss at only 7 hours i would not think.


You really don't need "special tools". Just your standard tool set should be fine.

More than likely your intake valve would be the tight one. You just need some shims ("washers") but you really don't know what shim to get until you measure how tight it is.

Oh yeah...the feeler gauge should be the metric one.

I have the manual with me. Just start working on it and I'll try to answer using the manual if you need help.

Just start taking the tank and top end cover off.

Then you need to set the cam chain aside. Don't lose it! Use a zip tie....

I'm going to search for the 250 valve adjustment thread now.

Thank you for your help so far.

I just finished reading the CRF250 valve adjustment thread. Wow!!! What a great thread. I sure hope Heckler does one on pistons/ring replacement.

Thank you very much for pointing me in the right direction. Checking the valves and even shimming will no longer be a problem.

I did discover one thing though. My torque wrench for my car is way too big.

Does anyone know of a good 1/4" digital in/lb torque wrench at a decent price that will cover all the torques on a CRF150R? The digital ones can switch from standard to metric at the flick of a switch and being that I am in Japan it will come in handy. There are so many low quality Chinese torque wrenches out there that I got lost in my search.

I completed my Valve Adjustment with no problems at all, but I did find that the Japanese and American Specs are different for the bike.


Intake 0.16 mm +-0.03

Exhaust 0.26 mm +-0.03


Intake 0.005 inches +-??

Exhaust 0.011 inches +-??

They don't match up on my feeler guages so it looks like ther is more allowable play than they show in the manuals.

I want to check my CRF150r valves. The thing is, once I get it apart and IF I need shims how do I proceed? Should I buy a shim kit for $90 or can I buy individual shims from Honda? I'm close to Honda, so at least I won't have to wait a week with the bike apart waiting for USPS.


You don' have to go buy a whole shim kit - her's a formula so that you can buy only what you need. A=(B-C) +D A:New shim thickness

B: Recorded valve clearance

C: Specified valve clearance

D: Old shim thickness

Example: Recorded valve clearance 0.001

Specified intake valve clearance is 0.006 + or -


A= (1-6)+190

A= -5+190


The correct shim would be 1.85

Hope this helps!

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