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Why bother with carb jetting a road bike

Posted: Sat Oct 17, 2015 10:47 am
by todd1996
Ok, im a new member but as ive been reading I seen many people who have completely different views on jetting. for example on my bike im replacing the air filter with a K&N and maybe down the line replacing my stock exhaust system. the thing is on both of these occasions it is said that there is no point to jetting but combined will it be necessary? it even seems like some people just automaticaly throw on bigger jets but as of now my bike is running beautifully and i dont wana mess it up.

any thoughts?

Re: Why bother with carb jetting a road bike

Posted: Sat Oct 17, 2015 2:21 pm
by bikemonkey
Speak to Rick Oliver, he knows just about everything about NC30's.

You'll probably need to re-jet to get the most out of your bike and stop it from running lean.

Re: Why bother with carb jetting a road bike

Posted: Sat Oct 17, 2015 6:55 pm
by todd1996
so how do i get in contact with this nc30 guru? :P

Re: Why bother with carb jetting a road bike

Posted: Sat Oct 17, 2015 7:06 pm
by bikemonkey
http://400greybike.com/forum/viewtopic. ... 2344c0eee6

His contact details are on the pricelist file download :up:

Re: Why bother with carb jetting a road bike

Posted: Sat Oct 17, 2015 10:25 pm
by todd1996
awesome :) we that's me sorted! so what kind of set up do you have?

Re: Why bother with carb jetting a road bike

Posted: Sun Oct 18, 2015 12:08 pm
by racingt
Hi, sounds like yours is sorted. Leave alone and enjoy.
Rejecting is done to remove the flat spot which is an issue preventing full enjoyment on the road.
Just ride:-)

Re: Why bother with carb jetting a road bike

Posted: Sun Oct 18, 2015 12:21 pm
by todd1996
sounds like good advice to me, i was tempted to get a moto maggot exhaust because im a sucker for loud bikes but dosen't seem worth the hassle.

Re: Why bother with carb jetting a road bike

Posted: Sun Oct 18, 2015 2:01 pm
by bikemonkey
I run 118 jets in the front carbs and 120 in the rear.

I have a standard intake and ethos half exhaust system.

Standard exhaust cans are very restrictive so even with a can change you'll need to re-jet.

The flat spot mentioned about doesn't have a lot to do with the jets, more the size of the washers underneath the carb needles.

You'd do well to talk to Rick about your set up and fully balance the carbs after any work you've done on them :up:

Re: Why bother with carb jetting a road bike

Posted: Sun Oct 18, 2015 5:23 pm
by todd1996
isnt 118f/120r the standard setup?

Re: Why bother with carb jetting a road bike

Posted: Sun Oct 18, 2015 6:58 pm
by bikemonkey
It is, I thought I had that mixed up.....

120F and 122R.