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1Back to top Go down    Thickest valve shim? on Sun May 01, 2016 9:46 pm

feo

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Long story made short-

I've got 3 tight exhaust valves, all at .20mm.

The shims weren't marked, when I measured with my micrometer, #3 cyl has a .132 inch shim. That works out to 3.35mm and change.

Thickest shim on the innerwebs I've found is 3.10mm

Don't think I want to try running .45mm lash.

Got something else to try, but in the meantime, What's the thickest shim anyone has seen in a K-bike engine?

    

2Back to top Go down    Re: Thickest valve shim? on Sun May 01, 2016 10:06 pm

RicK G

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The thickist 29mm shim I have ever seen is a 3.20mm. Not sure if BMW has a 3.20 but Kawasaki has that size in a 29mm shim.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

3Back to top Go down    For 16V they are 2.50mm through on Sun May 01, 2016 11:35 pm

Two Wheels Better

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For 8V K100 (& all K75) they are available in 2.0mm through 3.0mm sizes. For 16V they are 2.50mm through 3.20mm.

It's always a good idea to have your bike's year & model specifics in your signature so the question can be answered with some accuracy.


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'77 R75/7-1000cc, '87 K100RS, '93 K12 Big Block, '94 R100 Mystic, '03 K1200GT, '04 R1150RT, '06 K1200R, '07 K1200R & '09 K1300GT
    

4Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 12:10 am

feo

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Two Wheels Better wrote:
It's always a good idea to have your bike's year & model specifics in your signature so the question can be answered with some accuracy.

Sorry about that, overlooked that.

1990 K75RT, 65,000 miles on odometer (if it can be believed, LOL)

Since I pulled the camshaft, I also got to check differences in the shim buckets. I may have a solution with that.

Has anyone swapped buckets between bores on purpose? Not just absent-mindedly.

Would an exhaust clearance of .33mm-.35mm be a major problem?

    

5Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 12:34 am

Holister

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You gotta ask yourself why it needs a thick shim like that to begin with. I'd say at 3.35mm it's out of spec. The thickest shim Motorworks sell is 3.00mm.
Possibly the end of the valve stem is worn??
What do the other shims measure?
Are the old shims dished? You need to measure in the middle of the shim.

The place I buy my shims from in Melbourne AU have 29mm flat shims from 1.40 thru to 4.50 in 0.05mm increments @ AU$10 each.


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1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

6Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 12:51 am

feo

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I'm a bit confused by it, I don't remember ever dealing with a shim thicker than 3.00mm on Kawasakis when I worked on them (back when K-bikes were new on the market).

End of the valve stem looks good and feels good. I'm not willing to pull the head at this point to investigate root causes. Yet. Laughing

The other shims were 2.85 and 2.8, I've got proper size replacements for them in my parts stash (KLR650 leftovers).

I'm gonna take a brand-new 2.60 Kawasaki shim and use it to compare bucket-to-bucket differences in the morning before work.

I'll try to report back tomorrow night.


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1990 K75RT, more before it, more to come. GF's 1991 K75RT will be my maintenance job for a long time to come.
    

7Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 1:11 am

Holister

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feo wrote:I'm a bit confused by it, I don't remember ever dealing with a shim thicker than 3.00mm on Kawasakis when I worked on them (back when K-bikes were new on the market).

End of the valve stem looks good and feels good. I'm not willing to pull the head at this point to investigate root causes. Yet. Laughing
I don't think you'd actuall 'see' the wear on a valve stem end. You'd have to measure it.
How about the buckets? any wear there?


The other shims were 2.85 and 2.8, I've got proper size replacements for them in my parts stash (KLR650 leftovers).
2.80 & 2.85 sounds a little thick also but the fact that one is hugely different at 3.35 may indicate there's a problem.
All my exhaust shims are around the same at an average of 2.50mm


I'm gonna take a brand-new 2.60 Kawasaki shim and use it to compare bucket-to-bucket differences in the morning before work.

I'll try to report back tomorrow night.


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

8Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 2:59 am

charlie99

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unless someone did some work to the head and recut the valve seats ...and reground the valves .....then cut too much off the valve length to compensate ?


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9Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 4:10 am

Snod Blatter

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Kaptain Holister wrote:2.80 & 2.85 sounds a little thick also but the fact that one is hugely different at 3.35 may indicate there's a problem.
All my exhaust shims are around the same at an average of 2.50mm
Yeah, this! I've just replaced three shims, two exhausts and one inlet, and they were all 2.5mm and I've replaced them all with 2.45mm. This is totally normal, as I'm sure you know.

With shims so thick do they sit proud of the bucket? Perhaps the cam is no longer straight? All very strange!


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10Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 10:27 am

feo

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Well, it's amazing what a night's sleep and no home improvement projects can do.

Like reading a micrometer right.

Grrrrrrr.

It was .1032, NOT .132.

I unpacked a new 2.60 Kawasaki shim, and as soon as I had it in hand and felt it, I knew I'd screwed up.

The actual shims were 2.55, 2.55 and 2.60.

They've been replaced with 2.45, 2.45 and 2.50, I now have .30mm clearance on all exhausts.

I really am one of those people that function best mentally in the mornings.

Shocked


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1990 K75RT, more before it, more to come. GF's 1991 K75RT will be my maintenance job for a long time to come.
    

11Back to top Go down    Re: Thickest valve shim? on Mon May 02, 2016 6:59 pm

Holister

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Good to hear it's sorted and it didn't turn into a major repair. Often its the simplest thing.


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1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

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