Hi to all, have been reading through loads of posts here and have established (I think), that my bike is running a bit rich.

Starts and ticks over fine, good pull on the flat until I hit 7k then it starts to splutter. Also, I have a slow turning uphill section on my road and when I pull the throttle to get up the hill it just bogs down and struggles. I have tried a stock air filter and the bike was almost unrideable. Have changed the plugs and oil/filter and cleaned and replaced the K&N.

The bike is a NC29L, I have a aftermarket stainless 4-1 fitted with a standard end can, and there is a K&N insert air filter fitted. Have had a look in the carbs and the main jets are 116's.

Can anyone tell me if this sounds like the right jet size for whats fitted?

If so, can anyone suggest what else to try to cure the problem? If not, what size should I have? and where might be the best place to supply them?

Many thanks to you all in advance, this forum in a mine of information.

Welcome

Both L and N models main jets are 108.

Pilot jets are 35.

Im sure the Dynojet kit mains are 112 and 116. Also if the needles have grooves in them its looks like there has been a Dynojet kit fitted. I ran a dynojet kit and never needed the 116 jets and that was with an aftermarket silencer and K&N.

This thread will help also you:
http://400greybike.cc/forum/viewtopic.php?f=28&t=29736

Thanks , very helpful thread that. I would like to go back to factory spec as I have a new air filter element. Do you think I would need larger jets just for a 4-1 over the standard 4-2-1?

Its possible your 4-1 is causing the flat spot you have at 7000. Its generally thought that 4-2-1 is best for this bike. Maybe someones tried to compansate by putting 116s in hoping that would cure this.