CRF's Only Forums

Hey everyone,

I have an 07 CRF-150R that I need some advice as to what to do. I checked my valves about 3-4 months ago and one of the valves was way off. We shimmed that valve up to about the biggest shim possible. (Sorry if this is a little a unclear....I am no mechanic) So, my bike is definitely needing some sort valve job. My friend is trying to talk me into just installing a big bore kit. He thinks it will only cost a few hundred dollars more than just replacing the valves. Anyone have any ideas? Anyone know about how much this would cost? Thanks for all your help.

big bore kit won't fix your valve problems as a head is not part of a big bore kit. perhaps he's suggesting getting a new head with valves installed? we have them here:

http://www.crfsonly.com/catalog/product ... ts_id/3738

however, if your head is in good condition then you would save by going with a valve job and replacing needed valve components. if you go that route definitely have us do the valve work. we can do the valve job and supply you all the parts necessary.

ken

If you need a new head the kit Ken pointed you to is the way to go. It has the Kibblewhite vales/springs which will help minimize (not eliminate) the valve maintenance. Ken can also help you get the right gasket kit and anything else you need, like a service manual.

Having a shop bolt on the kit is one thing, but I would never let them do work on the valves. Even at that, you would still be better to buy a manual, a few tools, and learn maintain the top end yourself. It is really not that difficult if you can follow the directions.

While your at it, you probably need a new piston, cam chain, and chain tensioner (Ken can get these as well). Out of everything, the chain would be the most difficult because of the need to pull the flywheel which can be a little intimidating.

Post back what you decide to do. Plenty of folks on the site will be more than happy to help guide you past any rough spots. Asking questions before you take certain steps (like how to pull the flywheel) is highly recommended.

Hey, just out of curiosity, what happens if you don't do a valve job? Does it do a lot more damage eventually or will the bike just not run? I'm definitely not planning on doing that, I was just wondering....

depending on how badly your valve seats are banged up you might not get a good valve seal and that would make it difficult to start and perform poorly. regardless how badly they are banged up the new valves won't last a long. the valve job is the least expensive part of this so it's money well spent.

ken

EMX wrote:Hey, just out of curiosity, what happens if you don't do a valve job? Does it do a lot more damage eventually or will the bike just not run? I'm definitely not planning on doing that, I was just wondering....

Bike will loose compression, but you can still bump start it usually. If you do that and continue to ride, then your going to ruin your head.

What kind are the OEM valves? Steel, Titanium, Stainless? I am going to check the valves & seats for wear. If needing to replace, which kind of valve is better to install?

Don...you really can't visually inspect the valve seats for wear or the need to cut unless they have been damaged in some obvious way.

The stock valves are steel, all four. See my other post in response to this question.

Ken