NC30 missing / bogging, 8 -12k worse at partial throttle

[b1hrider]

hi,
just bought the bike, and it misses, like it's starving of fuel mebbe, mostly apparent between about 8 to 12k revs. On a wide ope throttle in lower gears it get's through, but in higher gears it's a struggle. Awful to ride on part throttle like cornering, one min it's tipping in due to it slowing down, then it clears and starts accelerating!
Had new plugs, coils and leads prior to my purchase, decided to strip carbs having read all about the needles and jets that should be fitted.

Dunno what sorta needle this is, but not what i expected!
Has 118's in front, 120's in back, on a viper race can with a db killer. This was new, and after sundays ride is well sooty, looking like it's running rich??
Any advice on the needles?
Idle and pick up is absolutely spot on, till it hits the point where it feels like a cylinder off.
Cheers!

[Cammo]

No idea what sort of needle it is, but some (i.e. dynojet) are known to cause running issues.

I wouldn't be surprised if that needle in the pic wasn't even intended for nc30 carbs, the taper on it's mental.

The needles will be an issue - you have a couple of options:
1. Stick a wanted ad in the classifieds for some standard needles.
2. Get some of Rick Oliver's aftermarket road nc30 needles which are known to work well.

Rick's contact details are in the stock list in this link: viewtopic.php?f=22&t=26174

Make sure you have a standard Honda paper air filter fitted, some aftermarket air filters can cause these sorts of midrange running issues too.

Jet sizes sound fine, this should be a fairly simple issue to resolve let us know how you go.

[b1hrider]

Cheers Cammo, and my thanks for your carb removal and strip guide! Currently fighting with rounded screws, ordered a set of stainless ones to replace them all with. Got one of the other slides off, and that has same adjustable needle in it too. Presume the original needles are not available or astronomically priced?
Determined to get this thing going right, seems the two owners before me never managed, one of which i think was on here strangely!
Thanks.

[b1hrider]

All screws now freed off, and have ordered a set of road needles from Rick Oliver, hopefully they'll be here for the weekend to join in the fun with a tin of carb cleaner and an airline before testing it again!

[Cammo]

Good move, hope it sorts it.

[b1hrider]

So, cleaned out the carbs and fit the rick oliver needles. Took it for a blast up the bypass. Fine now higher up the rev range, but now seems to have a similar problem up to about 5k. Will assess it properly tomorrow on ride out. Didn't fit any additional washers as recommended by R.O. but I gather some bikes need the extra one, some don't.
Carbs weren't dirty inside, the only thing I didn't do was remove floats or check height.
Any advice?
Cheers!

[b1hrider]

Right then, this mornings ride was a nightmare. Awful throttle response all over the rev range, didn't seem to matter where the needle was, once I'd come off the throttle and back on it there was a huge hesitation before it cleared.
After much annoyance I sussed out that rather than a particular rev range, the problem is at a particular throttle opening regardless of revs. Obviously this made attempting to feather the throttle in corners interesting to say the least!
Basically up to maybe a 1/4 is fine, from there to half is berr be berr berr running like crap, once past half or two thirds it's miles better, still sometimes feels like it's holding back a bit though.
Tailpipe sooted up to buggery, so still seems way too rich? On this basis, tried it briefly with baffle out thinking it would lean out a bit, seemed a little bit better but not had an extended ride where things become more apparent.
Any ideas, pleeeease!
Graham.