Valve cam clearance

[LoHo]

In my Clymer's, page 44 gives the clearances as .21-.24mm exhaust, .16-.20mm intake.
On page 56, it states .01-.04mm intake, .025-.55mm exhaust.

What the hell?

[rover]

valve clearances

The first group you have listed should be in inch decimals (thousands of an inch). The second group is in millimeters. These appear to be correct.

[Prisoner6]

Hey, LoHo -

Don't have the Clymer's manual in front of me right now, but I do know that the correct valve clearances (measured with the engine stone cold) for the 1980G in your signature should be:

Intake - .11-.15mm (earlier models were .16-.20mm)
Exhaust - .21-.25mm

Hope that helps ...

[Ken Talbot]

Ignore the table on page 56 - it looks like it was done by somebody who was having a bad day. The info on page 44 corresponds with the info in the quick reference section on page v11 at the front of the book - stick with that. I cant imagine how noisy an engine would be with exhaust valves at 0.55mm!

[BA80]

Valve clearances in inches......


intake (78 - 79) .006 - .008

intake (80 and up) .004 - .006

exhaust all years .008 - .010

[LoHo]

Yeah Ken, those are so far off that they must mean something else, although I can't think of what. The "0.01-0.04mm" for the intakes is what got my attention. Just a little bit of wear would cause the intakes to be open almost throughout the cycle. I actually bought another set of gauges because none of the ones I had went at low as .04mm. I have adjusted them correctly before, but used this site as my guide.

[BA80]

Valve clearances in inches......


intake (78 - 79) .006 - .008

intake (80 and up) .004 - .006

exhaust all years .008 - .010

Tune up specs on page VII in the front of the Clymers.

[ViperRon]

In doing this adjustment it is very important not to mix oranges and apples. The metric mm feeler gauge setting is very different from inches. Thousandth's and mm are very different so for the non mechanic its very important to not let this confuse a person. Most gauges have metric one side and inches the other. the specks given by Greg Ba80 are thousandth's what I use and are correct. It is very hard to get all at like .006 since the shims are in 5 mm increments about .002 thousandths. More often you will have one you either have it at .007 or .005 and can not get .006 as long as you are within the spec .006-.008 it will run fine.

[BA80]

You'll want to set them on the wide side anyway Ron. They will close up as they wear. I have one intake that ended up a little too wide and is noisy when the oil thins but is getting quieter as I put on miles.

[LoHo]

I am kosher with the inches verses mm; what stunned me was the numbers I saw in the spec list. I replaced three bent valves after f***ing up the ACCT (long story) and wondered what difference the new valves would make in the valve clearances. When I saw the .01-.04mm, I wondered how I could be so far out. The .04mm was the smallest gauge I could find. I returned to this list and looked up valve adjustment threads and realized the numbers were scarily different, hence my looking elsewhere in the manual and this thread. Everything looks much better now, and I only need to change one shim.

Any idea what the numbers on page 56 could be referencing?

[ViperRon]

Some Clymer books were just printed wrong and there is also a torque spec for the rear wheel axle that is incorrect should be 108 ft lbs for the standard.

[motoman]

Some Clymer books were just printed wrong and there is also a torque spec for the rear wheel axle that is incorrect should be 108 ft lbs for the standard.

......plus incorrect torgue specs on swing-arm, clutch basket retaining bolts........list goes on.

[LoHo]

Is there a sticky page of the various issues? I have seen most of them over the years, but never noticed the cam specs until this time. Maybe a new thread...

[skids]

Is there a sticky page of the various issues? I have seen most of them over the years, but never noticed the cam specs until this time. Maybe a new thread...

You are right. There should be a "sticky" for the corrections.

[DiverRay]

LoHo, just go with the Yamaha specs from the correct book. If you need it, I can email some scans from the Yamaha manual to you so you always have them. PM me if you need it.