NC30 carby jetting - DIY guide

[V4beermonster]

where abouts are you pal?

[phil x]

Or leave the tank on put a small pipe on the fuel tap & suck for a couple of minutes

Phil

[SP2VFR]

Tint I'm In Sydney.tanks off so I'll just pour some fuel directly in that hose.what does the top hose do the one that connects on top right hand side on the tank next to the handle bar.

[SP2VFR]

Phil I got the tank off so I'll just pour some fuel n c what happens..

[V4beermonster]

its just a tank breather

[SP2VFR]

k guyz did all that pore fuel in the hose directly bike wount start...one thing i did that im doubting now when i clicked the carb needles back in the carb(turned 1/2 clockwise n they set nicely and the needle was moving up n down)but the plastic bit was stationary it did not move at all so whats the slide cover suppose to do since there is no moving parts or did i click it too much may b it was suppose to move with the slide cover spring..plz help further diagnoise is needed.....thanx

[vfrman]

The bowls will refill them self through gravity. The trick is bypassing the vacuum on the tap to get the fuel to flow out of the tank.

[paul.s]

a quick jetting question. my mrs nc30 a uk bike came with 33bhp restrictors fitted so i took the carbs off and removed them. now the inlet rubbers had seen better days so orderd and fitted a set of nc35 ones as said on here there easier to refit the carbs into than nc30 ones. (still took20 mins of swearing tho) anyway after reading this thread decided to open up the carbs and have a look and as it happens good job as it had the 120,s and 122 jets arse about face. the emulsions were a little confusing too as both apeared to have 4 holes one pair with four in a row and one pair with two then a gap then another two then i realised they allso had one hole at the bottom at 90 degrese to the other holes so assumed these to be the five hole ones. i built them all up and adjusted the pilot screws to two turns out they were a mix of settings between 1 and 2 turns. anyway i got it running and it seems really sweet but there seems to be a hesitation building revs up to about 5k. its pretty crisp above that its not exactly a flat spot more like a fealing that the throttle cables made of elastic. you open the throttle and the rising revs are a few seconds behind .now i never took the tops of as a, i can do this in situ and b, i didnt have my drills or any small spacer washers with me will drlling the slide and fitting the 0.5mm washers under the needles cure my problem? it feels lean at low revs as it improves slightly as it warms up . cheers folks

[spud]

a quick jetting question. my mrs nc30 a uk bike came with 33bhp restrictors fitted so i took the carbs off and removed them. now the inlet rubbers had seen better days so orderd and fitted a set of nc35 ones as said on here there easier to refit the carbs into than nc30 ones. (still took20 mins of swearing tho) anyway after reading this thread decided to open up the carbs and have a look and as it happens good job as it had the 120,s and 122 jets arse about face. the emulsions were a little confusing too as both apeared to have 4 holes one pair with four in a row and one pair with two then a gap then another two then i realised they allso had one hole at the bottom at 90 degrese to the other holes so assumed these to be the five hole ones. i built them all up and adjusted the pilot screws to two turns out they were a mix of settings between 1 and 2 turns. anyway i got it running and it seems really sweet but there seems to be a hesitation building revs up to about 5k. its pretty crisp above that its not exactly a flat spot more like a fealing that the throttle cables made of elastic. you open the throttle and the rising revs are a few seconds behind .now i never took the tops of as a, i can do this in situ and b, i didnt have my drills or any small spacer washers with me will drlling the slide and fitting the 0.5mm washers under the needles cure my problem? it feels lean at low revs as it improves slightly as it warms up . cheers folks

if i was you i would leave the slides alone as from my experience drilling the slides out did bugger all to the throttle responce , i had a pair of undrilled slides and a pair that had been drilled out and found that the stock slides gave better throttle responce , and the drilled slides made the throttle responce slower/lazy feeling , but thats just my experience as some peeps say it helped when they done the mod , so think it depends on ur bike as no bike of this age likes the same settings in my opinion ,

cheers sam

[paul.s]

cheers sam ill have to pull the tops of and see what i have as the jets/emulsions were in the wrong carbs the needles may be too. my slides might allready be drilled too. im thinking rhat raising the needles may richen the mid up and may help