NT carb tuning question

Zeeb

Member
Apr 10, 2018
31
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So, i got my build running, and its time to fine tune the carb.

Ive heard that the position of the fuel metering rod determines a/f ratio at part throttle, and the main jet size controls ratio at wide open (metering rod does nothing). However, ive noticed that where i place the retaining clip on the metering rod dramatically effects how high the engine revs at wide open, and effects how much exhaust smokes. It appears that the metering rod does play a role in a/f ratio at wide open throttle.

Is it really only the main jet controlling a/f ratio at wide open? I want to make sure i get the basic facts straight before i attempt tuning and possibly re-jetting.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
155
63
USA
yes, needle is past the deck at that point, but tuning should not be done until 2 or 3 hundred miles of run in is done (bike may go leaner as it runs in)
 

Zeeb

Member
Apr 10, 2018
31
2
8
29
Coolio. I have close to 300 miles on her now. I think ill do a plug chop and see where i need to go with jet sizes.
 

javy mcdees

Active Member
Jul 30, 2018
143
58
28
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finally got my nt carb running great and the last little tune it needed was a jet change to make it run sweet and all I needed to do that was a brass hammer I used and tune the crap out of it cause the slide would not slide back in after 2 hours of massaging and removing any burrs that would cause the slide to never slide back in. It is fine tuned now, with a runtong.