NC30 Restrictions?

[ls1vzssz]

I have asked this once before but I didnt really get a clear answer.

Now that I've fitted up an aftermarket can, I can really hear it running.
It seems to splutter a bit when I am doing slow speeds around town holding at
a constant slow throttle and on the highway I just end up changing gears
at 10k rpm since after this it feels as though its revving for no reason.

There is a definite flat spot around the 5k rpm mark, then picks up again, and then
dies again just after 10k rpm. On a cold cold morning it is hard to notice this and it
almost feels like a different bike. But most days this is how it runs during normal
20 degree celsius weather.

My question is, Is my nc30 restricted?

I know that it would most likely be speed restricted to 180km/h but this doesnt bother
me yet... lol

Would my nc30 possibly be restricted carby wise? The only info I can find suggests
that some nc30's were also restricted by means of small carby jets to reduce power output.
I have also been told by someone that there could possibly be intake restricters in place.
As well I believe that my carbs are in dire need of a good clean / tune and balance.

I really need some sort of idea on where to start with fixing these problems. When it comes
to carbs I am basically useless so it will be going into a shop. I dont wanna send it in for
a basic carby clean up and tune for it to come back not much better off with a hole in my pocket.
If there is some sort of restriction carby wise in place I need to know about it so this can be
done at the same time. Most of the bike shops around Australia know almost nothing about the
grey import so I am going to have to tell them exactly what I want done. Please help guys!!

Thanks in advance to those who respond.

[Cammo]

I have asked this once before but I didnt really get a clear answer.

Now that I've fitted up an aftermarket can, I can really hear it running.
It seems to splutter a bit when I am doing slow speeds around town holding at
a constant slow throttle and on the highway I just end up changing gears
at 10k rpm since after this it feels as though its revving for no reason.

There is a definite flat spot around the 5k rpm mark (this is quite normal, an extra 0.5mm washer under the carb needles will help fix this), then picks up again, and then
dies again just after 10k rpm (sounds like your main jets are too small. The only way to tell is to open up your carbs, Standard size jets on early [1989 model] bikes suffer from small jets big time). On a cold cold morning it is hard to notice this and it
almost feels like a different bike. But most days this is how it runs during normal
20 degree celsius weather. Definitely a sign of being too lean, up the size of your main jets, putting in #118 front and #120 rear will sort it out. Jets are easy to buy and install yourself.

My question is, Is my nc30 restricted? No, not likely.

I know that it would most likely be speed restricted to 180km/h but this doesnt bother
me yet... lol This is the only restriction that Jap bikes come with.

Would my nc30 possibly be restricted carby wise? The only info I can find suggests
that some nc30's were also restricted by means of small carby jets to reduce power output.
I have also been told by someone that there could possibly be intake restricters in place. NO.
As well I believe that my carbs are in dire need of a good clean / tune and balance.

I really need some sort of idea on where to start with fixing these problems. When it comes
to carbs I am basically useless so it will be going into a shop. I dont wanna send it in for
a basic carby clean up and tune for it to come back not much better off with a hole in my pocket.
If there is some sort of restriction carby wise in place I need to know about it so this can be
done at the same time. Most of the bike shops around Australia know almost nothing about the
grey import so I am going to have to tell them exactly what I want done. Please help guys!! There's better help on this forum than most Oz bike shops!

Thanks in advance to those who respond.

Mate PM me if you need help, simple but takes a bit of time the first time you do it. All easy problems to sort!

I've been meaning to post up a guide on how to do all this and more, away from home most of the week, but will get a pictorial posted next weekend which will help a whole lot.

[jmannau]

This is an old thread but the answer to the question about carby restrictions seems to be contradicted by the following video.

https://www.youtube.com/watch?v=96MBseb4B4Y

Im a newbie so can somebody provide an explanation?

[jmannau]

Update: It appears that in the UK various companies made their own restrictors which consisted of a washer in the carb connectors Etc.