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mc21 carbs


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fenton
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mc21 carbs

Wed Sep 06, 2006 4:43 pm » Post: #1 » Download Post

i know it will be on here somewere but i need to know what carb runs richer on the power jets i know there 75 72,s which carb does the bigger jet go Question and what size should the needles be and what noch should they be on for a standerd setup
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StephenRC45
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Wed Sep 06, 2006 5:03 pm » Post: #2 » Download Post

#1 72p, #2 75p

#1 is the top cylinder.
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fenton
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Wed Sep 06, 2006 5:11 pm » Post: #3 » Download Post

thanks mate do you know the needle settings
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StephenRC45
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Wed Sep 06, 2006 5:17 pm » Post: #4 » Download Post

Stock needles cant be altered, only the HRC ones have clips. If you have HRC needles though best place to start is clip 3.
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mick

 
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Wed Sep 06, 2006 6:50 pm » Post: #5 » Download Post

Tell you what mate, I'll bring the carbs as is so we can do a stright swap over of anything we might want to change.
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Chester362
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Wed Sep 06, 2006 6:56 pm » Post: #6 » Download Post

StephenRC45 wrote:Stock needles cant be altered, only the HRC ones have clips. If you have HRC needles though best place to start is clip 3.


I probably am mistaken but, I`m sure I remember reading somewhere of MC21 NSR`s with adjustable (stock) needles being sold in certain markets?
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Wed Sep 06, 2006 7:52 pm » Post: #7 » Download Post

Anyone know why they weren't all fitted with adjustable needles as stock? (and if some where, why them?) Was it a Honda 'anti-tamper' thing? Or is it normal to those slightly oddball NSR carbs? I've never had a stroker without adj' needles before and it's really frustrating.

Are the adj' needles available seperately, or only as part ofthe HRC kit? It's like selling a telly without a volume control if you ask me Confused

Cheers

Wb
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StephenRC45
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Wed Sep 06, 2006 7:58 pm » Post: #8 » Download Post

You can't fit adjustabe needles to stock carbs because the needle jams in the needle jet. You have to fit the HRC needle jet too which goes with the adjustable needles, Its longer so the needle can be adjusted.
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Andy
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Wed Sep 06, 2006 8:03 pm » Post: #9 » Download Post

Technical Resources - Stock NSR carburettor settings.

The needles are different in each carb on the later MC21's. (And all MC18's)

The NSR's come with fixed needles because as stock they carburate perfectly! Smile (As long as the motor is in good condition!)
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maxim
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Wed Sep 06, 2006 8:10 pm » Post: #10 » Download Post

wb wrote:Anyone know why they weren't all fitted with adjustable needles as stock? (and if some where, why them?) Was it a Honda 'anti-tamper' thing? Or is it normal to those slightly oddball NSR carbs? I've never had a stroker without adj' needles before and it's really frustrating.

Are the adj' needles available seperately, or only as part ofthe HRC kit? It's like selling a telly without a volume control if you ask me Confused

Cheers

Wb


Some stock SP's sold in Japan came with adjustable needles if they were sold at altitude apparently... I've read that too!
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StephenRC45
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Wed Sep 06, 2006 8:15 pm » Post: #11 » Download Post

I think that would be more of a dealer thing rather than Honda. We do the same with some Aprillia's.

I bet they just stuck a washer under them anyway.
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fenton
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Wed Sep 06, 2006 8:32 pm » Post: #12 » Download Post

right ive just had them off and stripped and all is ok so i put them back on went for a blast got it up a ton (thats all it will do) and the power starts serging Confused Question
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WACEY

 
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Wed Sep 06, 2006 8:37 pm » Post: #13 » Download Post

Could someone please tell me what stock main jets a mc21 runs on while your on the subject. I recently bought an one and it won't rev proper above 9k. any help would be appreciated.
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fenton
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Wed Sep 06, 2006 8:38 pm » Post: #14 » Download Post

its at the top of the page mate Laughing
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wb

 
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Wed Sep 06, 2006 8:52 pm » Post: #15 » Download Post

Andy wrote:
The NSR's come with fixed needles because as stock they carburate perfectly! Smile (As long as the motor is in good condition!)


Laughing That's all well and good, but who wants a stock one?

Thanks for the insights and clarifications fella's.

So is there room to experiment a bit with shims, then? I've not even had the tops off yet 'cos they look like like those 'orrible diapham carbs you get on diesels Shocked Does anyone have a good exploded diagram so I know what I'm dealing with? (I'm more used to mikuni's etc., with the cable-in-the-top-through-the-spring-to-the-slide kind of set up.)

Cheers

Wb
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