NC30 Emulstion Tubes and Needles

[porndoguk]

also you say crack it open, if i hold the revs at 6k whilsts follwing traffic etc it constantly barbles from the flooding missfire, so i doubt its the hole thats causing that problem becuase its constantly there not just when the throttle is cracked back so to speak.

[porndoguk]

Little update

right had a dig, i have 118 Keihins and 115 keihins, but would prefer to try the 116 if i can get them.

ricks needles measure bigger than the J51 A&Bs,

also longer in length too, so gonna go out on a tangent and swap the jets and needles if it cures it great but i wont know which did solve it or wether a joint effort from both but its a case of im sick of getting these things on and off, so wanna fit and forget :)

i have measured Rick O's needles and will make a spread sheet etc with this info, for future reference,

they dont seem to have the flat tapers that the J51's have and have more of an overall taper from start to finish rather than intermediate, i just measured the diametres from the under side of the cap in line with the same taper points of the J51's

[porndoguk]

Little update

right had a dig, i have 118 Keihins and 115 keihins, but would prefer to try the 116 if i can get them.

ricks needles measure bigger than the J51 A&Bs,

also longer in length too, so gonna go out on a tangent and swap the jets and needles if it cures it great but i wont know which did solve it or wether a joint effort from both but its a case of im sick of getting these things on and off, so wanna fit and forget :)

i have measured Rick O's needles and will make a spread sheet etc with this info, for future reference,

they dont seem to have the flat tapers that the J51's have and have more of an overall taper from start to finish rather than intermediate, i just measured the diametres from the under side of the cap in line with the same taper points of the J51's

Right!

Changed the jets to 115F 118R and Rick O needles have slightly improved the problem but it does lurk there still slightly.
last thing to try is remove the last washer! so that will leave me with NONE!

if i pop down and gear and then re open the throttle i hit the flat spot and it takes a second to respond, after its flooded my flat spot went from

so to recap on the improvements 5k to 6k with the one washer removed to 7k with alex witham needles and is now at 5.5k with smaller jets and Rick O's needles, but 80% less noticable i was trying to find the flat spot and was stuggling because its improved so much. so still contemplating maybe changing the rear jets to 115s

also snaped a pilot screw side where the screw driver slots in theve been fucked since i had the carbs and was ultra carefull, ive also use my compressor with the air duster gun today and given the carbs a once over with 140psi!

Your Thoughts guys?

much love brothers Rick

[CRM]

how did you get on then pal?
for what its worth my UK spec bike is now running a set of jap carbs based on the following spec
24 slides
std jap needles no washers
std tubes and all settings
115 front
116 rear

and it goes very very well, so well i would say its actually the quickest NC30/35 i have ever ridden with a very slight 5-6k full throttle hesitancy when warm, part throttle you cant feel it or when cooler, but it pulls up top like no other NC i have ridden

Bike spec is a standard UK spec bike with a good set of NC30 heads with some port cleaning, and RVF camshafts. thats it. standard air and standard UK pipe.

So curious to know how you found ricks needle kit and where in the rpm range it made the difference.

[porndoguk]

how did you get on then pal?
for what its worth my UK spec bike is now running a set of jap carbs based on the following spec
24 slides
std jap needles no washers
std tubes and all settings
115 front
116 rear

and it goes very very well, so well i would say its actually the quickest NC30/35 i have ever ridden with a very slight 5-6k full throttle hesitancy when warm, part throttle you cant feel it or when cooler, but it pulls up top like no other NC i have ridden

Bike spec is a standard UK spec bike with a good set of NC30 heads with some port cleaning, and RVF camshafts. thats it. standard air and standard UK pipe.

So curious to know how you found ricks needle kit and where in the rpm range it made the difference.

well done a few more miles this evening, and was hitting high rpm on the way home as i was pissed off with my mates that had fucked off without me, as i was putting my name down for some volentry security work at our MCC Rally.

but it does pull well it always has, and i dont feel any noticible difference between the the change in jets, it deffinatly doesn smell as rich, im gonna get the bike dynoed again in the next month or so, but will be better prepared tools, laptop etc, id like kev to have a look at my ignition curve for the ignitech as its on Stock +2 Map.

Ricks needles are a tad thicker thus stopping the overfueling issue, but im probally going to rip the last remaining washers out on my next carb removing mission to also swap the pilot jets over. this should fingers crossed stop the flat spot, if not lower it into the pilot zone so the midrange wont be affected.

problem with the differences because ive changed the jets and the needles i cant really see/feel whats made the difference. ill be getting a set of head on tuesday from Geoff, which ill be putting on over the winter along side a new exhaust, as i plan to ditch what i have then.

whats the crack with the nc24 slides? they metal arnt they?

[CRM]

no still plastic, but they are dished out at the top so when fully open the slides are clear and not blocking the inlet.
the UK slides are metal and have a red ring around them at the top

[porndoguk]

no still plastic, but they are dished out at the top so when fully open the slides are clear and not blocking the inlet.
the UK slides are metal and have a red ring around them at the top

oh, maybe a potensial buy for me in the future.

thanks Paul.

[reverse cylinder jim]

but they are dished out at the top so when fully open the slides are clear and not blocking the inlet.

No difference in height at full lift between either. The dished Nc24 slides just fill in the void at the sides to smooth out flow through the carb bodies.

[CRM]

thats what i meant jim - however not as well put

[CRM]

actually i just noticed a difference, 24 slides showed the flat spot slightly more but gave a stronger kick up top, almost power band like
the 30 slides using the same needles (just a straight back to back ride only changing the slides on the same carbs) was smoother in the midrange with a stronger mid area at the expense of the stronger rush feel up top.
still pulled well, just the 24 slides felt much more fun.

for a track bike i would be using 24 slides. i suspect it may also be because the rubber diaphram feels far thinner and as such you can flick the slides up and down by finger far easier with half the resistance.