NC30 Emulstion Tubes and Needles

[porndoguk]

right alex's needles in and 50miles tested flat spot still there.



what do i do next? i need measurements for RICK O's ones if they thiner then they wont do the job, need something to lean out the midrange as its STUPPIDLY rich at 5-6k where i do alot of riding!

[jetblack]

get it on a dyno. Anything else is just guess work...

shouldn't need more than an hour or so on the rollers to figure out what's happening.

[porndoguk]

get it on a dyno. Anything else is just guess work...

shouldn't need more than an hour or so on the rollers to figure out what's happening.

erm thats were it came from to start with mate

viewtopic.php?f=62&t=25949

[Cammo]

That is rich throughout the whole rev range - very strange! It must be putting a fair bit more fuel in for it to be that rich.

Have you checked for holes in the floats? Also check the the float valves and seats aren't worn perhaps?

Did you put Alex's emulsion tubes in? Any slop in the needles when in the tubes?

You can lean up the overall jetting by increasing the float height (less fuel in the bowl), not really recommended since it's probably covering up the issue, but a tool to use nonetheless.

If you still have trouble finding where all this extra fuel is coming from it might be easier to try and get more air in by using a freer flowing air filter?

[porndoguk]

That is rich throughout the whole rev range - very strange! It must be putting a fair bit more fuel in for it to be that rich.
you can see it go off the scale at 5-7k rpm!

Have you checked for holes in the floats? Also check the the float valves and seats aren't worn perhaps?
when i ultrasonically cleaned all the parts the floats "floated" so no holes

Did you put Alex's emulsion tubes in? Any slop in the needles when in the tubes?
the needles dont sit in the tube contrary to popular belief, they adjacent to in a T shape fashion

You can lean up the overall jetting by increasing the float height (less fuel in the bowl), not really recommended since it's probably covering up the issue, but a tool to use nonetheless.

If you still have trouble finding where all this extra fuel is coming from it might be easier to try and get more air in by using a freer flowing air filter?
i have a K&N Panel Filter Fitted and sealed into the box,

i was running 118F and 120R Keihin when Dynoed, now running 120RD front and back, im considering removeing the snorkel and the front section of the base plate to let more air in, i dont think enough air is getting in, and i havent been over crazy on the jetting front either im totally confussed as to why its running this way, my next option is to buy another set of carbs and try that?

[phil x]

Why not put in smaller mains & drop the needles?

Phil

[porndoguk]

Why not put in smaller mains & drop the needles?

Phil

if youd have read through this fully you would see my needles have been dropped,
i can put smaller mains in but then the bike would run wank,
it has a TYGA exhaust, Yamamoto rear, standard headers that have been polished, coated then bandaged and a K&N filter, slides drilled to 2.5mm Dia, 1 standard 0.5mm Washer, emulsions in the right places piliots to 2.25 each, crank breather removed and has a piper cross filter and closed on the airbox, the carbs have all been ultrasonically cleaned, float heights accuratley set, emulsions in the correct places etc,

really nothing else left to do really, other than another set of carbs. or get more air into the mix.


and its not as if i have it stupidly jetted. 120s on F&R thats not alot phil (with a kiss)

[porndoguk]

gonna try it with snorkel out and remove the front of the carb base plate, might manufacture a heat sheild too! carbs got really hot yesterday whilst riding which wont help the issues either.

[phil x]

Why not put in smaller mains & drop the needles?

Phil

if youd have read through this fully you would see my needles have been dropped,
i can put smaller mains in but then the bike would run wank,
it has a TYGA exhaust, Yamamoto rear, standard headers that have been polished, coated then bandaged and a K&N filter, slides drilled to 2.5mm Dia, 1 standard 0.5mm Washer, emulsions in the right places piliots to 2.25 each, crank breather removed and has a piper cross filter and closed on the airbox, the carbs have all been ultrasonically cleaned, float heights accuratley set, emulsions in the correct places etc,

really nothing else left to do really, other than another set of carbs. or get more air into the mix.


and its not as if i have it stupidly jetted. 120s on F&R thats not alot phil (with a kiss)

YES but it is running stupidly rich - why on earth do you think trying to correct the mixture by fitting smaller jets/lowering the needle would make it run wank

You say there is nothing left to do than getting another set of carbs or more air into the mix.
Another option would be to put less fuel into the mix.....

Phil

[porndoguk]

Why not put in smaller mains & drop the needles?

Phil

if youd have read through this fully you would see my needles have been dropped,
i can put smaller mains in but then the bike would run wank,
it has a TYGA exhaust, Yamamoto rear, standard headers that have been polished, coated then bandaged and a K&N filter, slides drilled to 2.5mm Dia, 1 standard 0.5mm Washer, emulsions in the right places piliots to 2.25 each, crank breather removed and has a piper cross filter and closed on the airbox, the carbs have all been ultrasonically cleaned, float heights accuratley set, emulsions in the correct places etc,

really nothing else left to do really, other than another set of carbs. or get more air into the mix.


and its not as if i have it stupidly jetted. 120s on F&R thats not alot phil (with a kiss)

YES but it is running stupidly rich - why on earth do you think trying to correct the mixture by fitting smaller jets/lowering the needle would make it run wank

You say there is nothing left to do than getting another set of carbs or more air into the mix.
Another option would be to put less fuel into the mix.....

Phil

why would i want to put smaller jets in? the jets arent to fault its something else. i know how the carbs work and yes bigger jets will make it more rich etc, and making them smaller will make it leaner, but its not the jets in question its just the MIDRANGE @ 5-6K where the fuel is passing the middle section of the needle,

also bear in mind that dyno graph was tested with a fucked chain which i knew was crap but not as bad as i discovered at the DYNO. so thats another reason why it isnt as smooth as it could or should have been, once ive rectified my midrange problem ill get it dynoed again.

i need bigger needles, i have some on there way from Rick Oliver and im going to measure them to see if there wider in the middle if so i guess problem solved.

the jets are suited to a free flowing and loud exhaust, 120s arent big dude standard UK NC30s run on 120/122,
and a K&N filter, the bike isnt running a standard exhaust and i have the K&N filter in to compensate for the richness,

(there are people running the same carb set up on standard exhaust and standard filter with no mods etc)

its only rich in the midrange, ive made changes since it was dynoed, ive removed a washer, ive tried 2 sets of needles, and ive put matching jets in front and rear,