 Shimming?
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Joined: Mar 2005
Posts: 35
Greenhorn
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OP
Greenhorn
Joined: Mar 2005
Posts: 35 |
everyone,
i just recently started to play with my bike, was waiting till it was paid off.
got a question,
what is this shimming of the carb all about?
i've used the carb calculator and saw shims.
it's a stock 04 America
question is do i need to shim or not, when retuning the carb?
it's stock, does it already have them in it or not?
thanks for your help
john
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Re: Shimming?
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Joined: Feb 2005
Posts: 691
Adjunct
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Adjunct
Joined: Feb 2005
Posts: 691 |
Check Tech Vault under "Intake/Carbs". Also Pat's (Dingua) site is great, at: http://www.dinqua.com/Triumph/carbs0.html
--Tom
02 TBA; 130 mains; TBS; Nology Coils&Wires;Unifilter/opened Airbox; -AI/snorkels; -2 baffles;Progressive 440s & Springs
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Re: Shimming?
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Joined: Feb 2007
Posts: 23,186 Likes: 55
Fe Butt
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Fe Butt
Joined: Feb 2007
Posts: 23,186 Likes: 55 |
If the bike has stock exhaust and airbox no shimming is required.
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Shimming?
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Joined: Mar 2007
Posts: 315
Adjunct
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Adjunct
Joined: Mar 2007
Posts: 315 |
so when would shimming be required? when there's hesitation at the throttle?
06 Speedmaster. Black and Sunset Red.
SS long slash, 135/45, AI out.
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Re: Shimming?
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Joined: Dec 2006
Posts: 113
Adjunct
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Adjunct
Joined: Dec 2006
Posts: 113 |
Shimming is used mainly when there is a lean condition at certain throttle positions (see the thread in this section). Basically it raises the needle slightly (richens) so more fuel flows at a given throttle position.
'05 TBA, Freak/152.5 mains/48 pilots/Gutted Shotguns/AI/Custom rear hangers-Chain Guard/Sport signals/Ness Mirrors/Kury pegs/Driver's Backrest/LOTS OF CHROME!
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Re: Shimming?
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Joined: Jan 2006
Posts: 3,606 Likes: 2
Loquacious
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Loquacious
Joined: Jan 2006
Posts: 3,606 Likes: 2 |
Quote:
If the bike has stock exhaust and airbox no shimming is required.
Not always true...
Thorn,
Shim's are small "washers" that go under the "head" of your carb needle. they raise the shaft out of the jet ever so slightly, richening the mixture...the most common use is for curing "flat spots" at the throtle (usually around 1/8-1/4 throtle position)...My stocker had a pretty bad flat spot ight from the dealer...but as I was changing the pipes, air filter, and jets I wasn't terribly concerned I eventually went with the TBS needles anyway and never used any shims..
Last edited by RobBA05; 05/16/2007 10:06 AM.
THE VOICE OF REASON
per: Stewart
AF&AM/Shriner/Scoutmaster
130/45 TBS 2shim SS Uni 18/42
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Re: Shimming?
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Joined: Mar 2007
Posts: 315
Adjunct
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Adjunct
Joined: Mar 2007
Posts: 315 |
Quote:
Quote:
If the bike has stock exhaust and airbox no shimming is required.
Not always true...
Thorn,
Shim's are small "washers" that go under the "head" of your carb needle. they raise the shaft out of the jet ever so slightly, richening the mixture...the most common use is for curing "flat spots" at the throtle (usually around 1/8-1/4 throtle position)...My stocker had a pretty bad flat spot ight from the dealer...but as I was changing the pipes, air filter, and jets I wasn't terribly concerned I eventually went with the TBS needles anyway and never used any shims..
there ya go johnny.
any hesitation when throttling or popping while riding would be jets correct?
06 Speedmaster. Black and Sunset Red.
SS long slash, 135/45, AI out.
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Re: Shimming?
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Joined: Jan 2006
Posts: 3,606 Likes: 2
Loquacious
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Loquacious
Joined: Jan 2006
Posts: 3,606 Likes: 2 |
Quote:
any hesitation when throttling or popping while riding would be jets correct?
Hesitation on throttling (flat spot) could be jets but most find a shim or needle change fixes this...but it could be jets...popping while riding could also be jets but most will find that if your in the "ball park" that the popping can be significantly reduced by turning the air mix screws out some...
THE VOICE OF REASON
per: Stewart
AF&AM/Shriner/Scoutmaster
130/45 TBS 2shim SS Uni 18/42
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Re: Shimming?
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Joined: Jan 2005
Posts: 9,223
Big Bore
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Big Bore
Joined: Jan 2005
Posts: 9,223 |
Depends on throttle position. It could also be the air mixture screw adjustment and the balance of the carbs.
Being as these carbs are vacumm assisted slides, they will never give you that snap when you hit the throttle. You roll onto the throttle.
"Never underestimate the power of human stupidity" - Robert Heinlein
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Re: Shimming?
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Joined: Feb 2007
Posts: 23,186 Likes: 55
Fe Butt
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Fe Butt
Joined: Feb 2007
Posts: 23,186 Likes: 55 |
There is also as Phil had said in the past drilling the slide. I haven't had mine apart yet to try this or even see if mine is a year that was already done to so I don't know how much it helps. But that give a little quicker response. I imagine because of the larger passage it allows the vacume to build faster raising the slide faster.
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Shimming?
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Joined: May 2007
Posts: 19
Complete Newb
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Complete Newb
Joined: May 2007
Posts: 19 |
I drilled mine with my bare hands & a paperclip.
been there, done that
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