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Trouble adjusting valves

Started by 1tinindian, February 21, 2012, 10:59:45 PM

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1tinindian

I admit that this is my first time adjusting valve clearance on a motorcycle, and without any first hand help to guide me, I'm hitting a brick wall with what I have up to this point.

I have used the files section on the forum, Yamaha service manual, and Haynes manual.

After what I believe is the correct way to check clearances, my numbers are HORRIBLE!
4 of the exhaust valves are so tight, I couldn't even get my smallest feeler gauge (.0015 inch) to slide between the cam and shim. 2 were at .004 and 2 were at .006

On the intake side, I have 6 valves at .004, 1 at .005, and 1 at .006.

I am very concerned about the 4 exhaust valves I can't even get a measurement on.

This tells me that there is a lot of adjustment needed...now on to my frustration.
I have the tool to hold down the valves in order to remove the shims, but I am not having any luck getting it positioned correctly. There has to be a trick to it, or my hold down tool isn't fitting like it should.

I am at your mercy, so if you have any advice to help me along, I'd really appreciate the helping hand.
I just wish I had someone here with me to show me where I'm going wrong.
Thanks.

Leon
"I want to be free to ride my machine without being hassled by the "man"!
91 FJ1200

nvmike24

I found that positioning the slot for easy access helped. The position of the lobe prior to installing the tool was VERY important. Lobe center even with the valve cover surface i.e. 90 degrees outward worked best for me. Hope this helps.
Mike Sweeney
83 CB1000C, SOLD
84 FJ1100, in little pieces, for powder coating, FZR1000 Front
Fork Mod and Trans repair!
12 Road Glide Ultra

markmartin


ddlewis

Hey Leon, I have bumbled through this operation several times.. That should give you confidence right there.

Quote from: 1tinindian on February 21, 2012, 10:59:45 PM...
After what I believe is the correct way to check clearances, my numbers are HORRIBLE!

Hard to get this wrong, just turn the crank CCW till all the cam lobes point up..  measure twixt the cam and the shim.

Quote from: 1tinindian on February 21, 2012, 10:59:45 PM...
I have the tool to hold down the valves in order to remove the shims, but I am not having any luck getting it positioned correctly. There has to be a trick to it, or my hold down tool isn't fitting like it should.

I remember that tool being a little fiddly.  Gotta get it just on the edge of the bucket.  iirc, don't tighten it down super tight and leave yourself a little play to work with.   Also don't turn motor without shims in the buckets, or the buckets will shave the corners off your lobes and you'll get little metal sprinkles in your motor.  DAMHIK, but I hear that's bad.

Dads_FJ

Quote from: ddlewis on February 22, 2012, 08:26:51 AM
Hey Leon, I have bumbled through this operation several times.. That should give you confidence right there.

Quote from: 1tinindian on February 21, 2012, 10:59:45 PM...
After what I believe is the correct way to check clearances, my numbers are HORRIBLE!

Hard to get this wrong, just turn the crank CCW till all the cam lobes point up..  measure twixt the cam and the shim.

Quote from: 1tinindian on February 21, 2012, 10:59:45 PM...
I have the tool to hold down the valves in order to remove the shims, but I am not having any luck getting it positioned correctly. There has to be a trick to it, or my hold down tool isn't fitting like it should.

I remember that tool being a little fiddly.  Gotta get it just on the edge of the bucket.  iirc, don't tighten it down super tight and leave yourself a little play to work with.   Also don't turn motor without shims in the buckets, or the buckets will shave the corners off your lobes and you'll get little metal sprinkles in your motor.  DAMHIK, but I hear that's bad.

Sure about that?  I'll have to look at the book, but I don't believe the valve clearence is measured with the lobes @ TDC:

"With the cover off the gasket's poor condition is even more obvious. The timing plate (brass bit with holes in it) is used to position the cam lobes at "Top Dead Centre" (TDC) so the valve clearances can be measured with a thickness gauge. Essentially, you want the lobes from the exhaust and inlet valves to face AWAY from eachother for each measurement. This is achieved by turning the motor until the timing mark (a "T" mark on the plate) lines up with the line on the timing sensor (grey thing on the right with a little silver magnet on its left side) for cylinder 1 (left). Then, you turn the engie 180 degrees anti-clockwise until the T mark faces AWAY from the timing sensor for cylinder 2. Another 180 degrees for cylinder 4, and a final 180 degrees for cylinder 3. This follows the firing sequence 1, 2, 4, 3."

Maybe that was the problem, that the lobes *were* at TDC while measurements were being made.
John S.

'84 Yamaha FJ1100
'89 Yamaha FJ1200
'92 Yamaha TDM850
'80 BMW R100S/Sidecar
'81 Yamaha IT250(H)
'77 Yamaha IT175(D)
'39 BSA WM20

1tinindian

Thanks, one and all.
My measurements were taken with the cam lobe at 90* to the shim surface for each valve.
This is the way it is shown in the manual.

How do I go about getting a measurement from the 4 exhaust valves that I couldn't even get a feeler to fit?
"I want to be free to ride my machine without being hassled by the "man"!
91 FJ1200

ddlewis

Quote from: Dads_FJ on February 22, 2012, 09:51:12 AM

Sure about that?  I'll have to look at the book, but I don't believe the valve clearence is measured with the lobes @ TDC:

"With the cover off the gasket's poor condition is even more obvious. The timing plate (brass bit with holes in it) is used to position the cam lobes at "Top Dead Centre" (TDC) so the valve clearances can be measured with a thickness gauge. Essentially, you want the lobes from the exhaust and inlet valves to face AWAY from eachother for each measurement. This is achieved by turning the motor until the timing mark (a "T" mark on the plate) lines up with the line on the timing sensor (grey thing on the right with a little silver magnet on its left side) for cylinder 1 (left). Then, you turn the engie 180 degrees anti-clockwise until the T mark faces AWAY from the timing sensor for cylinder 2. Another 180 degrees for cylinder 4, and a final 180 degrees for cylinder 3. This follows the firing sequence 1, 2, 4, 3."

Maybe that was the problem, that the lobes *were* at TDC while measurements were being made.

I didn't mean to say all 16 are up at once.  Just all 4/cylinder.  And as far pointing straight up vs slightly outward or inward, can't remember where the mark leaves them.  (My guess is that it doesn't matter - if you're off the lobe part the rest of it is round so you could measure anywhere.  Anybody know if that's true?)  Of course best play it safe and go by the "T" like the book says.



ddlewis

Quote from: 1tinindian on February 22, 2012, 11:54:30 AM
Thanks, one and all.
My measurements were taken with the cam lobe at 90* to the shim surface for each valve.
This is the way it is shown in the manual.

How do I go about getting a measurement from the 4 exhaust valves that I couldn't even get a feeler to fit?

hmm, good one.  How about - take the thinnest shim you have and put in those buckets.  hopefully you can get a feeler in and do your math from there.

andyb

Quote from: ddlewis on February 22, 2012, 12:18:56 PM
hmm, good one.  How about - take the thinnest shim you have and put in those buckets.  hopefully you can get a feeler in and do your math from there.

That's the one!

carey

QuoteThanks, one and all.
My measurements were taken with the cam lobe at 90* to the shim surface for each valve.
This is the way it is shown in the manual.

Leon,'

Check them again with the lobe 180 degree to the shim face and see what you get.  If you do have to change any, I found a set of pointy forceps/tweezers work well for getting the shim out, after the too lholds the bucket down.

Carey

1tinindian

Thank you all for taking time to give me a hand.

After trying several times to get the tool to fit, I come to realize that it needed to be slightly modified.
I gradually trimmed it down in the areas where it looked like there was interference....AND it worked.
It still took some fiddlin around, but I was able to pop the shims out with a small screwdriver that had a magnet on the tip, so it worked out real well.
I now have all of the shim sizes documented.
I have 8 at 270, 7 at 265, and 1 at 275.

Now I can try to figure out what my new sizes need to be to get things back in spec.

Leon
"I want to be free to ride my machine without being hassled by the "man"!
91 FJ1200

JCainFJ

 Carey has it correct, set the cam lobe 180 degree to the shim face. Yamaha cams have very long opening and closing ramps, so the base circle on them is centered opposite the lobe. Please do not use a magnet to lift the shim from the bucket. You don't want magnetized valve train parts.

simi_ed

Jon, I'll bite:  What's wrong with magnetized valve shims?  Is it because they will attract loose metal parts circulating?  Or some other  unseen reason?  Inquiring minds want to know!

Thanks!
-- RKBA Regards,

Ed
===
Ed Thiele 
Simi Valley, CA -- I no longer have SoCal manners.
'89 FJ12C (Theft deterrent Silver/White)


- All that is necessary for the forces of evil to win in the world is for
enough good men to do nothing.

- Edmund Burke

JCainFJ

Ed,
Yes, magnetized valve train parts can do alot of damage by attracting loose steel bits. The BMW tools for removing valve shims include a special pliers (needle nose with one tip ground very thin) for the job. When I did my advanced training we were warned about this.
In a related story, I have a friend with a Stearman biplane and the Continental R-670 engine failed at about 200 hours because the main bearing on the crankshaft was magnetized. The bearing came appart and destroyed everything inside the main housing! When my friend ordered a fresh engine the overhaul Co. had found that 90% of the NOS main bearings were strongly magnetized. A fresh R-670 was over $20,000 at the time! His prop also failed an inspection, but that's another story.