[stryker1080]

I have a question that i always wondered about, why is it that for bikes it is soo "important" to check the valves. Anyone that owns a car never has valve checked, ppl drive their car, do oil change and thats it... Put on 200,000+ km etc and never worry about it. I know the bikes rev alot higher than cars, but still the dealerships make it seam like ure engine is gona blow if you dont do it. Wouldnt it only cause a problem if they tighten up?

 

[jplynx]

been wondering about adjusting valves. my bike has 17000 miles and the manual says that it needs to be adjusted at 16000. the dealer wants 400+ to do it and my bike sounds and runs just fine. I've heard of people having problems after they get their valves adjusted. I'll probably get it adjusted when I have the money.

 

[James06CBR]

I had a 1985 Honda XL600 that I rode the crap out of for 15 years and put 3X the amount of miles you have. We checked the valves in 2000 for the first time and they needed no adjustment. In fact, everyone I have talked to has checked and nobody ever has needed to adjust..go figure. If things sound and feel fine, chances are you need not adjust. I wouldn't bother paying to have that done..follow a writeup on this...very simple process. Otherwise, save the money and do it at 20k if you are worried.

 

[tripage]

My brother checked his at 20,000 and his were fine, I haven't heard of anyone locally needing them adjusted.. $400 is way to high, it isn't that hard....You just need the right tools... If it runs and sounds fine leave it alone..

 

[slipper]

I have a question that i always wondered about, why is it that for bikes it is soo "important" to check the valves. Anyone that owns a car never has valve checked, ppl drive their car, do oil change and thats it... Put on 200,000+ km etc and never worry about it. I know the bikes rev alot higher than cars, but still the dealerships make it seam like ure engine is gona blow if you dont do it. Wouldnt it only cause a problem if they tighten up?

with dealer shop rates as high as $85/hour i can understand it costing $400 to perform a valve adjustment. Its not hard but very time consuming. When we talk about a "valve adjustment" we are actually talking about adjusting or shimming the valve lifters.

There are two types of lifters, the hydraulic and solid type. Most automobiles use a hydraulic type because of the minimal amount of maintanence required. Hydraulic lifters use oil to maintain a proper valve lash.

Some engines use solid lifters. These types require periodic adjustment to maintain specification. There are basically two types of solid lifter mechanisms. One type which the CBR600RR uses would require the addition or removal of shims to get the proper valve lash.

 

[NewRedRider]

Just to check the valve clearances shouldn't cost $400. It should cost about have that. But if they have to install new shims they have to pull the cams out which cost twice as much. Maybe their price was based on pulling the cams. If so remind them it's a Honda not a Ducati.

 

[abadfish]

If you get the courage to check the valves yourself, there is a tutorial stickied in this section. Its really not that difficult, just tedious and time consuming. Its very likely your valves won't need adjustment but the check is done to verify that.

 

[OveRReV]

i'd do mine if the time comes, i've been doing cars for a long time before i switched to bikes it's not any different, i've got all the tools including a digital caliper to measure shim thickness.

 

[raptor]

I have a question that i always wondered about, why is it that for bikes it is soo "important" to check the valves. Anyone that owns a car never has valve checked, ppl drive their car, do oil change and thats it... Put on 200,000+ km etc and never worry about it. I know the bikes rev alot higher than cars, but still the dealerships make it seam like ure engine is gona blow if you dont do it. Wouldnt it only cause a problem if they tighten up?

The thing about bikes is, as you state, that they rev higher. A LOT HIGHER! This means that parts undergo much higher decelerations, which causes them to "stretch" (undergo elastic / plastic displacement) of a greater magnitude than cars.

Coupled together with the higher compression ratio, you have a much greater chance of your valve hitting the piston. The high compression ratio means that the piston is closer to the cylinder head at top dead centre. If your valve clearance is wrong... Klap, snap, grind... No more engine.

And yes, putting in good oil at a regular interval will make a difference. Loose the lubrication between the cam and the shim, and it will grind it away in no-time. This may lead to the valve hitting the head hard instead of gliding into its seat --> Throw away the cylinder head or get it reseated and new valves put in.

A few bucks every few ten thousand km spent checking the valves vs a thousand for a new engine? I know which I'm choosing...

 

[stryker1080]

When the time comes i will do the check/adjustment as needed... Ive only worked on two strokes, doing top end rebuilds and such but im quite familiar with the general procedure of doing the valve adjustemnt...