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Richard Phillips
San Luis Obispo, CA
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Mikuni Question
#654182 05/25/16 9:26 am
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I have a 71 Commando with a single Mikuni set up. The bike was set up that way when I bought it and I have been chasing an odd throttle feel since I got it. When I start to roll on the throttle, it is very stiff at first and then it quickly gets nice and smooth. I have chased the cable from the grip to the carb and I can't see any kinks or sharp bends. The cable is nice and free when disconnected. It looks like the problem is in the carb, but I don't see anything obvious. Are all Mikuni's like this? If not, what is a good source for Mikuni parts if I want to go through it?

Thanks,

Doc


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's

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Re: Mikuni Question
Doc_dup1 #654185 05/25/16 9:39 am
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DOPE
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is the slide sticking, or is there a tight spot in the throttle barrel?

undo the cable and maybe see which end has the problem.

niche cycle has anything you need for mikunis. an offspring of MAP.


every day you do not take a chance is a day of your life that you will never get back.
Re: Mikuni Question
Doc_dup1 #654192 05/25/16 10:26 am
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I had a problem like this once
My Mikuni had high miles on it and the spring was very warn
It would distort and bind
the symptoms were like yours
HTH
Cheers
Dennis B


Member # 182
'73 750 Commando
'72 Combat Commando
'71 Triumph Blazer
'69 Victors
'68 Starfire
'51 Royal Enfield 250 'S'

Re: Mikuni Question
Doc_dup1 #654267 05/25/16 10:36 pm
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Thanks for the suggestions. When I pull on the cable, the spring feels to be pretty strong but I don't have any other Mikuni bikes to compare it to. I will pull the carb and look inside at the slide and barrel.

Thanks,

Doc


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's

Re: Mikuni Question
Doc_dup1 #654270 05/25/16 11:05 pm
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Also check how the cable, jet needle, and jet needle retainer are installed in the slide, and that the spring is seated centered at both ends. If I remember right, that jet needle retainer can be mistakenly installed upside-down. The tang should go downward.

In answer to your first question, a sticking slide is very untypical of Mikunis.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: Mikuni Question
Doc_dup1 #654295 05/26/16 4:19 am
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In Remembrance
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In Remembrance
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Accelerator pump?


Hate is a poison which one consumes hoping for another to die.
Re: Mikuni Question
stubbicatt R.I.P. #654559 05/28/16 12:01 am
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Originally Posted by stubbicatt
Accelerator pump?

Not normally fitted to those Norton kits. Probably a VM or TM, neither of which have accelerator pumps.


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
72 T120V cafe project "Mr. Jim"
72 T150V "Wotan"
Re: Mikuni Question
Doc_dup1 #654929 05/31/16 8:03 am
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There is also a friction adjustment built into most AMAL twist grips. You might back that off. Don't forget to add the grease between the twist grip and handlebar.


Don't hide 'em, Ride 'em !!

RF Whatley
Cornelia, GA
Re: Mikuni Question
Doc_dup1 #655007 05/31/16 6:16 pm
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Thanks everyone, everything is clean and re-lubed. The problem is still there. I may try a new cable just for reference.

Doc


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's


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