hi, i have recently rebuilt my nc30 over the last 2months after a winter stip down, service and new exhaust. Before i stripped it down i was having a sort of splutter/bog around 5k-6k revs when opened the throttle from partial throttle, it would only be for a second and then pick up and go.

After servicing the bike (new oil, plugs, air filter, valve clearances) and new carb rubbers, RO needles and 120 main jets all around, the bike was great for like 300 miles or so untill now. The splutter has returned, and now worse than ever, and happens at 4-7k now aswell...

Its only when the bikes up to temperature by the way, bike rides fine when its cold.

I have no idea whats causing it and find it really annoying when riding, does any one have any thoughts as to what it could be, and how it can be sorted.

Any help appreciated.

Thanks Matt

Out of interest, why did you go for 120 mains all round?

Probably worth a dyno run to see what's going on with the fuelling.

Was recommended 120 mains all round by rick oliver to suit a full tyga system.

Yeah wouldnt mind a dyno run, just need to find one close enough.

matt_nc30 wrote:Yeah wouldnt mind a dyno run, just need to find one close enough.

where are you based?

when were your valve clearances last checked ? i had one NC30 that again when cold was perfect, when warm had a difficult spot to pass around 6 - 8k and sounded like a slider was rattling in the carb. clearances set, sorted.

banoffee wrote:

matt_nc30 wrote:Yeah wouldnt mind a dyno run, just need to find one close enough.

where are you based?

i am based in swansea, south wales


The valve clearances were just done before putting the bike back together.

The bike will rev fine, doesnt bog or anything if i just accelerate, it revs smoothly. Its just when im at crusing speeds, holidng 6.5K rpm and then a roll-on will cause it to splutter.

float heights correct? if everything else is good i'd try raising the float heights by 1-2mm to lower the fuel level a bit, sounds like it might be bogging down (too rich) when warmed up.

Did you clean out the carb jets and tubes as part of the rebuild?

Yeah, the carb was cleaned and new main jets put in.

I dont understand how it has been fine for first 300 miles and only now its bogging

matt_nc30 wrote:Yeah, the carb was cleaned and new main jets put in.

I dont understand how it has been fine for first 300 miles and only now its bogging

Oh it was fine.

Maybe you have some crap in the tank thats worked its way down to the carbs and is blocking one of your jets.

Inline fuel filter would help if this is the problem...