arite ive fanaly got to test ride my nc30 today after rebuilding it over winter and it seems to have a misfire around 11,000 rpm its great at low revs but when it gets to 11k it just wont do anything could this be because of a restricter stoping it, it does have the m-max box on it but that may have failed. please help thanx

The NC30s misfire about 5500rpm if the restrictor box isnt working so this doesnt sound like the case.

What did you do in your rebuild..

It could be lots of things, ususual suspects would be carb system / electrical system (ie battery / reg-rec) or the coils.

on the carbs theyve been rejeted to cope with the full system the needles have been raised its got a drilled air box on it to allow a bit more air in there. The jets are 120 bk and 122 at the front i think or oposit way round carnt remember. By puting the air box on would this make it run lean creating the misfire thanx

Josh312 wrote:on the carbs theyve been rejeted to cope with the full system the needles have been raised its got a drilled air box on it to allow a bit more air in there. The jets are 120 bk and 122 at the front i think or oposit way round carnt remember. By puting the air box on would this make it run lean creating the misfire thanx

Drilled Airbox?

nobody i know has this mod on an NC30 buddy, if it was a worthy one it would be documented.

id stick a standard box/lid on, only holes you want are on the baseplate an optional K&N filter,
do a search i have one fitted on mine and its breathing much better etc.

sounds like the holes maybe causing your problems. what exhaust do you have on it?

ill be going to the dyno next weekend so will see what happens.

Hi, my airbox lid is drilled, has three 12mm holes either side, and i raised the tank 5mm, sounds ace but makes no differance performance wise as far as i can tell. I cant remember wat size jets i got in mine at the mo tho, sorry.
If you want to see if it the holes making the differance just take tank off and tape them up.
Cheers
Ian

all sorted it was the fuel breather been blocked thanx every1