I need a simples guide to carb mods with end can

Harrismag · Post by **Harrismag** » Tue Mar 17, 2009 10:41 pm

Hi all,
Just building my 1st NC30, and need quick advise. I am geting a 2nd hand std pipe with Micron end can. Assume I have std carbs from F reg model, what is the best jetting and carb mods?. Do I use standard air filter? I'm not after power but would like it to run sweet.

Thanks in advance. Simples

Post by **Cammo** » Tue Mar 17, 2009 10:46 pm

A good starting point for your muffler is to run 118f/120r main jets, pilot screws 2.25 turns out, and install an extra 0.5mm washer under the needles (total 1.0mm),

If you run a standard filter and airbox this is a good combo and has always run sweet for me.

Post by **royster81** » Wed Mar 18, 2009 8:56 am

or a good running setting for me was 116f/118r main jets, pilot screws 2.50 turns out, and no extra washer under the needles (total 0.5mm),slide holes left at 2mm.

and i am running a standard filter and airbox and this is a good combo and has always run sweet for me.

Harrismag · Post by **Harrismag** » Wed Mar 18, 2009 7:43 pm

Thanks for the advice. Has anyone taken it a stage further with drilling the slides and the thicker washer, or does this cause the motor to run rougher?. As I have said before I'm not interested in outright power as I have another bike for the power. I just would like it to pull clean from low down, with a nice bit of acceleration if possible.

Out of interest what is the top speed with silencer mod on the NC?

Cheers

Post by **royster81** » Wed Mar 18, 2009 8:26 pm

i did both and my bike hated it ,but others have done both and swear by it, so i do have been trying to keep the slides 2mm

Post by **Sligeach** » Thu Mar 19, 2009 11:55 am

PM me, i have a guide in word format i can email on to ya, i think

Post by **Spike16** » Thu Mar 19, 2009 9:33 pm

ok iv clean my carbs up and currently my main jets are 120 front and back, have 0.5mm washers under needles (standard i believe) and 2mm holes

what should i do?

try the bike like this then have a go with the extra 0.5mm washers, then with 2.5mm slides aswell as washers then with different jets?

or get extra washer under needle, 2.5mm slide and mess about with jets from their?

also do the pilot jets get changes at all or are they standard? and do the needle jet holders get changed to suit setup or are they also standard?

Post by **Cammo** » Fri Mar 20, 2009 4:12 am

Spike16 wrote:ok iv clean my carbs up and currently my main jets are 120 front and back, have 0.5mm washers under needles (standard i believe) and 2mm holes

what should i do?

Spike, you should only change anything if it needs it.

Firstly, set the pilot screws to 2.25 turns out. Yours might only need to be 2 turns out depending on exhaust setup (freer flowing half/full system usually requires richening [more turns out]). You can tell if it's correct usually by off idle performance. There's a big difference bewteen performance on correct setting and wrong setting.

Main jets are most important as the engine is under max load when they're in use, it it's lean you can do engine damage. So, this is the first thing to get right (assuming your float levels are in spec).

A very rough way is to try various sizes, and take it for a spin. Keep going up/down in size until you get max performance then settle for 1 size larger for safety's sake (and weather conditions, etc). Or, take it to a dyno who will do much the same thing except they can do it in the one spot. Both ways take time, hence dyno costs.

Needles are easy when using standard needles (i.e. no alternative diameters). Stick an extra washer in and see if it performs better. Seat of the pants doesn't always tell the true story, use a timer when acclerating 3 gear roll ons etc if you want to really get it right

Lastly, forget modifying the slides until you have the jets and needles setup correct. Drilling the slides has no effect on fuelling or running performance, do it once you have evrything correct, if you don't like it replace them with standard slides.

Pilot jets and emulsion tubes don't need to be changed with your setup. Doing so will mess all other jetting up.

Important: Do one thing at a time only, starting with the most critical. It's not hard but you do need to be methodical about it.

Harrismag · Post by **Harrismag** » Wed Apr 01, 2009 9:17 pm

Right at last I managed to get time to look at my carbs. This bike is new to me so I have never touched it!. it is runnung 110 alll round front and rear (a star marked in front of no.?). With Star 35 emulsion tubes. It did have a standard system on it. Is this what jets they ran in Japan?

Cheers

Post by **Cammo** » Wed Apr 01, 2009 9:24 pm

Harrismag wrote:it is runnung 110 alll round front and rear (a star marked in front of no.?). With Star 35 emulsion tubes. It did have a standard system on it. Is this what jets they ran in Japan?

This is standard for early (K) model nc30's. They run lean as with those jets from the factory you should change them while you can. The 'star' is the Keihin symbol.

Swap them for 118 front and 120 rear, that will suit your aftermarket end can if you keep the standard filter.

I need a simples guide to carb mods with end can

I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can

Re: I need a simples guide to carb mods with end can