valve adjustment

[Azylum]

it has recently come to my attention that the valves on bikes need to be periodocally adjusted. how often should this be done? and why do they need to be adjusted? because of the constant high rpms? (sorry for dumb questions, still new to the sport).:nod:

[Patrick]

Valves need to be adjusted regularly, depending on the bike, anywhere from every 4000 miles,(V Star 650) to 26,000 miles (R1)

The reasons are varied, but all have to do to wear, i.e.:
As your valve bangs into it's seat during the normal process of running, the valve sinks deeper into the seat, reducing the clearance between the cam and the valve.
Another scenario: Over time and normal wear, material is lost from the cam cap, cam lobe, shim bucket etc, and clearance increases.

Valve adjustments run from easy: Screw and lock nut,
to involved: Shim under bucket, requiring cam removal for shim replacement, to ridiculous; Ducatis Desmo system.

With todays poor excuse for gasoline with Ethanol, we're seeing more and more engines with tight valve clearances.
Occasionally we'll check a bike and the valves don't need to be adjusted. When that occurs I charge a reduced rate for just inspecting the valves.

Other services that should be performed at the same time are: replace plugs, synch carbs / throttle bodies, check TPS, and replace / service the air filter.

I hope I answered your questions.

[Patrick]

BTW, typical GSXR valve adjustment interval is every 15,000 miles.

[TxBritt08R1]

why don't bike engines have hydraulic lash adjusters to take up excessive clearance, because of valve float at high rpm?

Britt

[Patrick]

Exactly!
Some of the lower revving cruiser bikes have hydraulic valves, but a high performance bike engine can't because of the potential for lifter pump up or excessive bleed down at higher RPM.
The last high revving bike with hydraulic valves I can remember was the Nighthawk S back in the late '80's.

[MagnaMan]

Speaking for the Magna contingent (Honda V4), and shim and bucket valve design, it's a two-stage process. First you check the valves. If they need adjustment then you have to pull the cams and change the shims. (Not something I want to do).

The service interval is 16,000 miles for valve adjustment. However, Magna engines have never needed adjustment until around 40,000 miles. I was skeptical of this claim from other owners so I pulled my valve covers and checked at 16K. Everything was within tolerance. Another owner I know had his checked by the dealership at 28K and still no adjust was needed. However they charged him for the full amount of time as if they had made adjustments.

As Patrick pointed out they don't charge the full amount if the bike does not need adjustment. I would take your bike to a shop like that. You might also want to get on a forum specific to your bike type and see when other owners have needed valve adjustments.

[stlal]

I have the shim under bucket design on my f4. Too me, checking the clearances is more of a pain in the ass then changing the shims. Some of them are in a tight spot.

[Greg in H-town]

The Ninja 250 needs it every 6K or so, but it's pretty easy to do - I did them myself and the main deal was getting the bike apart to get in there. I did the valves and the carb sync and it ran great when I was done. They're so easy to work on even *I* can do it. :icon_thum

Not so sure about the ZZR, though. Patrick, I know you told me once before but what is the valve adjustment interval on the ZZR?

[Azylum]

thanks patrick, thats exactly the info i was looking for.

[level5]

Another owner I know had his checked by the dealership at 28K and still no adjust was needed. However they charged him for the full amount of time as if they had made adjustments.

As Patrick pointed out they don't charge the full amount if the bike does not need adjustment. I would take your bike to a shop like that. You might also want to get on a forum specific to your bike type and see when other owners have needed valve adjustments.

:nod: :nod: :nod:

I hate dealers for this type of reasons. They say that you need adjustment at 15K miles and didn't do shit to it and make you pay an arm or leg for it.:angry7:

[jrock]

What is the typical price for this service at MU?

[Patrick]

Depends on the bike. Send me a PM or give me a call.:icon_thum