Should I adjust my valves?

[ty454]

I posted this under under the technical section but got only one response. I think I saw a few dust bunnies while I was in there....

Well I was convinced that this winter I would have to adjust my valves - my bike has 28k miles on it and last spring when i checked they were getting close to the loose end of tolerances.

So today I took her apart and checked the clearances. Here's what I found:

5 exhaust valves at .305mm (.012")
2 intake valves at .203mm (.008")

The remaining valves were within clearance levels. Last time I checked, those exact valves had the same readings so they haven't moved in the last year. Technically those 7 valves are right on the borderline for being considered loose, although Suzuki says exhaust valves are loose at .310mm and intake valves are loose at .210mm.

So the question is - should I go through all the effort of pulling the cams myself (dealer is not an option) to try and bring them further in spec? I don't plan on checking the clearances again for another ~7-10k miles (or next winter, whichever comes first).

My dad, a motorcycle mechanic from the days or old says he doesn't think it's worth it since they're still that close to being in tolerance and are on the loose end instead of the tight end.

What's the consensus here? Should I go through that effort now or revisit it when I check them next time?

 

[da busa guy]

i'm with your dad, i'd let them ride.

 

[StageRulz]

i'm with your dad, i'd let them ride.

+1



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[JINKSTER]

They are to the "Loose Side" eh?....well here's my thoughts...unless I'm all screwed up?....valve clearances don't "Get Looser With Age/Wear"...the get "Tighter"...from the repetitious peening affect of the valve face against the valve seat...hence the stem moves higher...thereby moving the shim under bucket to a higher position...thereby "Closing" the tolerance gap (too tight) and not "Opening" the tolerance gap (too loose).

a little "Too Loose": can and will steal a little performance...but...

a little "Too Tight": can come dangerously close to the shimmed bucket (with a little valve face/valve seat wear) causing it to eventually rest up against the cam lobe "Circle Base" and could burn valves on the exhaust side and not fully closing on the intake side which would begin to cause notable power losses.

This was typical off all previous bikes I've owned but this is my first Suzuki...it was also typical that after break in and the first valve adjustments?...they all seemed to stay put real well.

L8R, Bill.

 

[ty454]

They are to the "Loose Side" eh?....well here's my thoughts...unless I'm all screwed up?....valve clearances don't "Get Looser With Age/Wear"...the get "Tighter"...from the repetitious peening affect of the valve face against the valve seat...hence the stem moves higher...thereby moving the shim under bucket to a higher position...thereby "Closing" the tolerance gap (too tight) and not "Opening" the tolerance gap (too loose).

a little "Too Loose": can and will steal a little performance...but...

a little "Too Tight": can come dangerously close to the shimmed bucket (with a little valve face/valve seat wear) causing it to eventually rest up against the cam lobe "Circle Base" and could burn valves on the exhaust side and not fully closing on the intake side which would begin to cause notable power losses.

This was typical off all previous bikes I've owned but this is my first Suzuki...it was also typical that after break in and the first valve adjustments?...they all seemed to stay put real well.

L8R, Bill.

I don't know, the numbers don't lie. Maybe my bike is getting newer with age?

 

[JINKSTER]

They are to the "Loose Side" eh?....well here's my thoughts...unless I'm all screwed up?....valve clearances don't "Get Looser With Age/Wear"...the get "Tighter"...from the repetitious peening affect of the valve face against the valve seat...hence the stem moves higher...thereby moving the shim under bucket to a higher position...thereby "Closing" the tolerance gap (too tight) and not "Opening" the tolerance gap (too loose).

a little "Too Loose": can and will steal a little performance...but...

a little "Too Tight": can come dangerously close to the shimmed bucket (with a little valve face/valve seat wear) causing it to eventually rest up against the cam lobe "Circle Base" and could burn valves on the exhaust side and not fully closing on the intake side which would begin to cause notable power losses.

This was typical off all previous bikes I've owned but this is my first Suzuki...it was also typical that after break in and the first valve adjustments?...they all seemed to stay put real well.

L8R, Bill.

I don't know, the numbers don't lie.  Maybe my bike is getting newer with age?  

Maybe not as..I've not seen it yet so it's only rumor status but...I've heard that on the busa if you hit the rev limiter on occassion?...that "Peening Of The Valve Stems" can occur..and this would indeed cause the reverse of what I've encountered on my previously owned bikes and peened valve stems would cause the valves OAL to shorten and the clearances to grow looser....therefore...disregard anything I've said here until someone with first hand busa valve knowledge comes along as...I'm curious to know the myths from fact here as well.

L8R, Bill.

 

[Lloyd]

I dont check or adjust them anymore unless it is noisy for some reason or wont idol good....

Bill, the cam could be wearing down...

 

[JINKSTER]

I dont check or adjust them anymore unless it is noisy for some reason or wont idol good....

Bill, the cam could be wearing down...

ya mean the cam bearings?...cause as I understand it?..."The Circle Base" area is never supposed to come in contact with the shim/buckets....now the lobes can wear but not the circle base..and as I understand it the circle base is where you check valve clearance specs...correct?

L8R, Bill.

 

[Lloyd]

Yup, All moving parts wear. meaning greater tolerances can be achieved. Crappy oil?..... Always mic the shims before install also, both shims..The surface can wear if it was 2 tight at one time..Not likely, though..

How many overhead cam cars get the valves EVER checked in their lifetime? Not that they run the rpms of these machines, but I don't run red line on my Busa ever..I get scared..

 

[Lloyd]

Also what says it was in spec when new..

 

[ty454]

Also what says it was in spec when new..

No doubt. I've maybe redlined it twice since I've owned the bike (bought it new) and rarely ever get above 5k rpms.

 

[Gunnybusa]

Also what says it was in spec when new..

No doubt.  I've maybe redlined it twice since I've owned the bike (bought it new) and rarely ever get above 5k rpms.

The power is up above 7,oooRPM. twist that throttle open ty454

 

[rubbersidedown]

Busa's rarely need valve adjustment. Even most dealerships dont see the need to adjust them at the sheduled check,its usually not nessecary. If you've checked 'em,and they aren't noisey...no worries. I had over fifty thousand clicks on my Busa , never one adjustment,not a single bucket.

hav a good 1...RSD