Valve Shim Adjustment

Hey everyone,

First off, thanks to all who contributed to the Airhead Valve adjustment DIY. Like everything else, I could not have performed it without this site.

However, I'm kicking myself for two reasons:

I used metric feelers. I swore that is what I was supposed to use, but was I wrong?

My Measurements came to:

Exhaust 1: .152 feeler fits, .178 does not. (Current Shim is Y280, need Y285)
Exhaust 2: .178 feeler fits, .203 does not. (So I'm ok)
Exhaust 3: .102 feeler fits, .127 does not. (Current Shim is Y 265, Need Y260)
Exhaust 4: .127 Feeler fits, .152 does not. (Current Shim is Y265, need Y260)

Intake 1: .127 feeler fits, .152 does not
Intake 2: .127 feeler fits, .152 does not
Intake 3: .127 feeler fits, .152 does not
Intake 4: .127 feeler fits, .152 does not

Also, Though I bought a demagnetizer for the picks I used to help move the shims, I had dropped one of the picks and it picked up fine metal shavings from my basement floor.

Did I magnetize my shims? If so, what can I do? I must have used a faulty demagnetizer huh?

Anyway, I would appreciate the help guys. I'd hate to know that I did it wrong but...I'd like to know and remedy before I move to the Church of Clean.

Thanks in advance for the help!

 

I wanted to include pictures of the chart I made, as well as the Spark Plugs 1-4 (left to right).

Note that the left exhaust fell off due to rust, so It had been running with only one can for about 200 miles. Could that explain why two plugs are black, and two look decent? Thanks!

 

You did not use metric feeler gauges. You used SAE gauges that were marked with the metric equivalent to the SAE measurement.

 

Rats. Please understand that this is my first time wrenching on something like this so even my tool knowledge is limited, and thanks for the response.

Despite my error, wouldn't it seem as though I could technically replace the three "out of spec" shims and be within the proper limits?

Also, does anyone have a remedy for my possible magnetic error?

Thanks

 

If you round the measurements to two places and then read the chart you'll be fine. As for the magnetized shim: just give it a rap with a hammer, or drop it onto the workbench to demagnetize it.

 

Don't worry about the shim being magnetized. Yamaha manual even says use a magnet to retrieve them. THe cam pounding the daylights out of the shim will probably degauss it anyway. Besides.....there's a magnet in the oil drain bolt that will catch anything anyway.

Dave F

 

Thanks a lot guys. Lastly,should I be worried about the inconsistency in those plugs?

Thanks

 

Not until your valves are in spec, your float levels properly wet-set, the carbs cleaned and refurbed and you're working on doing a running vacuum sync. Until then, anything's possible.

And you didn't use a metric feeler gauge; you used an American set with (oddball) metric equivalents printed on it. You can make life much easier if you use an actual METRIC feeler gauge set such as the K-D/Gearwrench pn 2274 which is widely available. The blades are metric, period.

 

yup yup yup

 

Thanks guys. Unless someone tells me otherwise, I'm going to change only the three exhaust shims that I noted above. Even though the measurements are wonky and have a "wide" range from one to the next, everything else appears to be in spec aside from the three exhaust shims noted above. This puts me in spec, no?

My carbs are nearly disassembled and I'd like to get everything running properly before I start to really modify the bike, which is why I don't want to re-measure the shims.

Coming up next is going to be a detailed photo journal of my carb disassembly, cleaning, and reassembly (following the gospel of the Church of Clean). I figure it's the least I can to to contribute. (I will start a new thread in the next few days).

 

I'd take another look at exhaust 1--- not very common to go to a thicker shim.....

I don't know what your measurements are, and I'm not going to do the conversions either. Measure in metric and tell us what they are, then we can help more easily.

 

Back at it! After ordering the Feeler Gauge from Chacal, I went and remeasured the valve clearances and compared them to the chart. I calculated the below:

Exhaust 1: .15 mm feeler fits, .18 mm does not. (Current Shim is Y280, need 275)
Exhaust 2: .18 mm feeler fits, .20 mm does not. (So I'm in Spec?)
Exhaust 3: .08 mm feeler fits, .09 mm does not. (Current Shim is Y 265, Chart calls for Y255)
Exhaust 4: .13 mm Feeler fits, .15 mm fits with some pressure, .18 mm does not (Current Shim is Y265, so, what is anyone's take on this? Should I keep it, or go to a 260. Chart says .11~.15 needs 260)

Intake 1: .10 mm feeler fits, .13mm does not (In Spec)
Intake 2: .13 mm feeler fits, .15 mm does not (In Spec)
Intake 3: .15 mm feeler fits (with pressure), .18 mm does not (Current Shim is Y290, Chart says .16 to .20 needs shim 295. Should I go to 295 just in case?)
Intake 4: .10 mm feeler fits, .13 mm fits (with pressure) 15 mm does not. (In Spec)

Does everything look correct? I'm worried about exhaust 3 because it's so far off from the others, and also worried about exhaust four shim due to how close it is to being in or out of spec.



Hopefully what I've provided is enough for a little guidance. Thanks!

 

Intake spec is .11mm~.15mm, Exhaust spec is .16mm~.20mm.
There is some confusion going on here. Double check that your numbers are correct for I and E then we can help. Intake valves are closest to the carbs. Exhaust valves are closest to the headers.

Gary H.

 

All numbers are correct. My feeler gauges go from .9 mm - .10 mm - .13 mm - .15 mm

That is why I am including which gauges fit and which don't, to be as clear as possible.

Thanks

 

You'll need more than just 4 feelers......

Don't tell us what fits and what doesn't..........we need to know WHAT THE CLEARANCE IS----example:

>Exhaust 1: .15 mm feeler fits, .18 mm does not.

In spec is .16-.20mm SO......does .16mm fit? Or .17mm? If so, it's still in spec. If .15mm fits, but not .16mm, then it's out of spec.

Some of your assumptions are good, others are not. Example:


>Intake 1: .10 mm feeler fits, .13mm does not (In Spec)NOT true...if .11mm doesn't fit, it's not in spec
>Intake 2: .13 mm feeler fits, .15 mm does not (In Spec) TRUE......good assumption

It's called a 'check' because that is what you're doing.......checking to see if things are in or out of spec. If it's in spec, it's in spec and it can wait til the next check. If its out, it's out. If it's so borderline, then it MAY be possible to do now, but keep in mind that if you put it to far out of spec the OTHER way, it can make a clearance too BIG, and THAT can create problems.

If you're religious about doing your checks, then it's not a problem to wait til the next check for one that's a little close to the tighter end of 'still-in-spec'. There's enough clearance to begin with, that you could end up going down two sizes instead of one the next time depending on how much you ride.

You're not going to have to worry about piston-valve interference. Think about it.....the clearances are getting tighter because the valves recede into the head. If they are receding into the head, they are moving AWAY from the piston. So, piston-valve clearance is INCREASING. The pistons can only hit the valves when shims are replaced with THICKER shims.

So, all of that said.....give us SPECIFIC measurements.

Dave F

 

Brosef, what Dave is saying is correct. And although the feeler gauges you have include the blade size selectiona as you noted, they also have smaller sizes (.03mm, .04mm, .05mm, etc.) which can be siamesed together to create the "in-between" sizes (.12mm, .14mm, etc.) that you'll need to acquire a specific clearance.

 

DOH! I never thought of that! Thanks so much for the help Len and Dave, I have no idea what I'd do without some of you guys. Looks like I'm going back under that valve cover to measure for a third time. Will report back!

 

Third times the charm?

Intake 1: .11mm
Intake 2: .13mm
Intake 3: .13mm
Intake 4: .11mm

Therefore all intakes are in spec.

Exhaust 1: .15 mm (Current shim is: Y280) NEEDS: Y275
Exhaust 2: .17mm (In spec)
Exhaust 3: .06mm (current shim is Y265) NEEDS:Y255
Exhaust 4: .13mm (current shim is Y265) NEEDS Y260

I think that's all. Thanks everyone.

 

You got it now!

 

I'll go take a look in the shim pool and see if I have what you need..... I'll get back here in about half an hour-----

Dave f