ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Guys:
Checked my valve shim clearances tonight and found I have one intake and one exhaust valve out of spec. The markings on the shims were gone. Used a neighbors digital caliper to measure.
On the Intake:
Clearance: 0.13
Original Shim: .293 - .294
Pat's Shim Calculator says I need: 2.885
Exhaust:
Clearance: .32
Original Shim: 2.84 - 2.85
Pat's Calculator says I need: 2.885
To be honest, I'm still a little baffled about how this works, can someone confirm what shims I need to order? (also a good reason why I'm in the restaurant management business not aerospace engineering...)
Thanks!
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Al
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Daughters boyfriend is helping me with this. He says I need:
Exhaust - 2.92
Intake - 2.925 or 2.93
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Al
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tomv
Adjunct
Reged: 02/01/05
Posts: 674
Loc: Huntsville, AL, USA
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Intake valve spec is .15 to .20mm. You need more clearance since you have only .13mm. Therefore you need a thinner shim to give you more clearance. To get to a clearance of .175 (the midpoint) you would need to go .045 thinner on your shim. (.175-.130=.045)
If your current shim is about 2.935mm, the right shim size should be as close to 2.89mm as possible(2.935-.045=2.89)
For the exhaust, the valve clearance is supposed to be .25 to .30mm or .275mm midpoint. Therefore with .32mm clearance (.32-.275=.045) you have .045 too much clearance and need a thicker shim. You need (.045+2.845=2.89) a shim as close to 2.89mm as you can get.
I have not done it yet, but I have been reading about how to do my valves now also. Good luck,
--Tom
PS: I am an aerospace engineer.
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--Tom
02 TBA; 130 mains; TBS; Nology Coils&Wires;Unifilter/opened Airbox; -AI/snorkels; -2 baffles;Progressive 440s & Springs
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bigbill
Loquacious
Reged: 01/11/05
Posts: 4700
Loc: Las Vegas, Nevada
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Looks to me like you might be able to switch the two and be in spec.
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Hostes alienigeni me abduxerunt. Qui annus est?
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vegas
Adjunct
Reged: 06/26/05
Posts: 305
Loc: Las Vegas, Nevada
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Just would like to know how the heck these valve clearences get tighter? Seems to me they should only get wider.If I measured a tighter clearence than spec's I would suspect incorrect measuring or incorrect math or both.Also if/when I was doing it I think I would shim to the tight side of spec's, cause it should only get wider as time goes on. Vegas
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Tom & Guys:
Thanks for the input, always pays to get advice from a professional! <g>
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Al
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chy
Loquacious
Reged: 01/11/05
Posts: 2804
Loc: Dahlonega Ga.
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The valves recess into the valve seats and that decreases the clearance.
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Blue
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Since we couldn't read the markings on either shim, we assumed the shim became smaller as the measured number was a non-standard size for either (as read from the caliper). The guy helping me asked if Triumph cut shims to fit each bike, that seemed unlikely but who knows?
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Al
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Both of those valves out of spec were on the right cylinder. When I bought the bike with 1,200 miles, the AI was still intact and the carbs had not been set (A/F screws). The right cylinder A/F screw was completely closed, the left was open a bit. Wonder if that super-lean condition on the right side had anything to do with that cylinder being out of spec? Guessing it would have to be a factor?
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Al
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bonnyusa
Big Bore
Reged: 01/11/05
Posts: 9207
Loc: Ft. Liquordale, Fl.
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Hey Al,
Like bigbill said, you should be able to swap the shims. I did this last year and the offending valves were spot on after...
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"Never underestimate the power of human stupidity" - Robert Heinlein
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Since I already have the cams out, I ordered shims. The local Triumph counter guy didn't appear too savy on these items. He said the closest was a 2.90 shim. Do you think that is OK?
Al
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Al
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bonnyusa
Big Bore
Reged: 01/11/05
Posts: 9207
Loc: Ft. Liquordale, Fl.
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Since it's so easy to put the cams back in, I would swap the shims, bolt the cams back down, spin the motor (by hand), and re-check your clearances.
You may be able to cancel your order....
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"Never underestimate the power of human stupidity" - Robert Heinlein
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Might just do that, thanks for the tips!
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Al
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Dinqua
Check Pants
Reged: 01/11/05
Posts: 5866
Loc: Honeoye, New York
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The shims only come in increments of 0.025mm. Therefore, by swapping the existing shims you have you will be pretty darned close.
Consider if you are tight or loose then match accordingly. Say you are tight, then if the shim you need is in the middle of one of the 0.025 increments, go with a thinner of the two to give more room (looseness) for the final result. I use the mid points in my Dinkulator as ststed above, that is the middle of the road so you have slop at either end to work with. I also try to get them as close to the same as well. By that I mean i want all the exhaust gaps to match and all the intake gaps to match.
When we did Matt's, he had 6 out of spec, but 4 were interchangable to work so only 2 were actually needed in the long run.
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2003 Speedmaster / 2001 Trophy 1200
Crusher of Dreams and Nads
Pat
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ssjones
Saddle Sore
Reged: 01/11/05
Posts: 5043
Loc: Hagerstown, MD
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Thanks Pat. I decided against reusing the old shims in opposite cylinders until my order comes in. I don't have the o-ring for the oil tube or the copper washers, so I might as well wait. My local dealer said they would be in next week by mid-week, I can wait until then.
We tried using your Dinkulator with the mid-points, than again at the low with both ends of the spectrum.
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Al
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bigbill
Loquacious
Reged: 01/11/05
Posts: 4700
Loc: Las Vegas, Nevada
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To elaborate on what Chy said, the valve faces and seats wear more rapidly than the cam and shim do.
Wondering now; Do the valves have rotators?
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Hostes alienigeni me abduxerunt. Qui annus est?
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bonnyusa
Big Bore
Reged: 01/11/05
Posts: 9207
Loc: Ft. Liquordale, Fl.
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Quote:
Wondering now; Do the valves have rotators?
Nope.
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"Never underestimate the power of human stupidity" - Robert Heinlein
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