What size carb should I use?

ChiefMongrel

New Member
Aug 20, 2015
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Tigard, Or
I'm runnin a port and polished china girl 80, with a fred head and kx80 expansion chamber exhaust with ( I think, its been awhile) 36T sprocket. She's been runnin the stock NT with the choke half open, and I was thinking she could handle about an 18mm instead of the stock 14mm. Anywho, I just scored a fantastic deal on a complete and operational mikuni 20, and am hopeful it will work. If it dont, I will resell it, but I would like to hear your thoughts on whether you think it will work or not. Thanks.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,621
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83
Los Angeles, CA.
That 20mm MIkuni should work well, but you'll have to re-jet it. (& you'll also have to get a manifold for it).

Now... reading that you have to have the choke 1/2 on on your stock carb tells me that you need to re-jet that one too!
 
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Nate&Brandi

New Member
Aug 24, 2018
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33
I agree familiarize yourself with jetting first and get your stock carb runNing good because once you step into the bigger carbs it's a whole different ball game you have not only a main jet you also have a idle or "slow" jet as well as an air/fuel mixture screw and the slide needle and there is a certain order in which you must tune each one I won't get into huge detail on that becausend it would take too many pages and time to explain. Just get a grip on jetting your stock carb first. You have to learn to walk before you can run my friend. Good luck
 
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ChiefMongrel

New Member
Aug 20, 2015
3
0
1
Tigard, Or
That 20mm MIkuni should work well, but you'll have to re-jet it. (& you'll also have to get a manifold for it).

Now... reading that you have to have the choke 1/2 on on your stock carb tells me that you need to re-jet that one too!
That 20mm MIkuni should work well, but you'll have to re-jet it. (& you'll also have to get a manifold for it).

Now... reading that you have to have the choke 1/2 on on your stock carb tells me that you need to re-jet that one too!
 

Tyler6357

Well-Known Member
Mar 15, 2012
1,143
170
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Santa Barbara, CA
I just got a Mikuni but it's only 17mm so it will fit on my piston type reed valve. I haven't tried it yet, I don't have any other jets except stock and I'm not even sure what size the stock jets are. I'm certain I will have to change at least the main one.
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
176
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midwest
i prefer the nt or nt clones for simplicity. they also preform better than the other carbs i tried. the other carbs have advantages, but i still prefer the power the nt carb gives over the others, also again the simplicity of the nt carb.

edit: i also run a custom manifold on my bike i built myself. it's longer and fatter, then shrinks down to match the intake port. gives me a sweet low and mid range, great torque for the hills and trails. welded it up myself, i love it.