NC35 Missfire in the midrange. HELP!

[Harryredchow]

I know these sort of issues are tricky to resolve, but here goes.

My NC35 has developed a misfire around 5-8K. It gets worse after riding for a long period and I suspected fueling. I had the bike on a dyno and there wasn’t anything suspect with the fueling, but the dyno guy couldn’t get a stable reading on the dyno tacho on the front HT lead. Since then I have tried the following.

Pulled plugs. Good spark on all of them and they look brand new. Better than my spares.
New reg/rec
New battery
Fitted 2K resistor on speedo to derestrict, just in case there was an issue with the restrictor speed sensor.

I now have a coil pack on order, just in case this is breaking down under heat/load.

Does anybody else have any suggestions? It’s beginning to get on my nerves now.

Cheers.

[Harryredchow]

Right, coils made no odds. I now believe it is due to fueling. It runs OK at the top end, but when you open the throttle in the midrange it just bogs and pops before taking off. I did try dropping the needles, but I found it wasn't much of an improvement. Could it be running lean in the midrange?

It is an NC35 fitted with an Ethos twin exhaust. Filter and filter box is standard. Jets and needles are those Kenso shite. Previous owner must have fitted them.

Seems nobody has any standard needles. Does anybody know if any of the HRC needles is a close match to the stock needles?

[speedy231278]

Is the snorkel fitted to the airbox, and has it been modified at all? That can sometimes make them a little fluffy, but to be honest from what I've read before, you're probably looking at those jets and needles needing a lot of playing with to get the thing running right.

DSS have the needles listed as a five week wait, so I guess they're buried deep in a warehouse in Japan or possibly Honda themselves get them to order from elsewhere. They're also, yikes, £31.19 each (16027-mr8-900).

Rick Oliver lists a 'road' needle set for the 30 and 35 for £40, so that may be a more affordable option....

[Harryredchow]

Thanks for the reply. I have managed to source some needles secondhand and some 115 mains from RO. I am waiting for them to arrive and I am going back to as close to standard as possible. The 115 mains may be a bit big, but at least it wont be lean.

Those Kenso Jet kits are shite. I have raised the needles and it pulled strong up top, but barked and farted through the midrange. When I lowered them they were OK in the midrange, but weak at the top. On a cold morning it fuels OK, but once warmed up is a pig. I suspect you are right about the fueling. Back to almost base setup for me and see how it goes.

I have also been tempted to find a standard exhaust system. I love the Ethos twin pipes, but I also like the silence of a standard system...along with the easy tuning.

[Harryredchow]

Also, it has a standard airbox and filter and has the rubber flaps still fitted. It has some interesting Japanese mods. I suspect the Japanese owner was a bit of a tinkerer. The rearsets are £500, the exhaust must have cost a packet, even the little indicators on the rear are nice (standard wont fit with the exhaust), but the jet kit was a few Yen too far. He should have stopped there :)

[Neosophist]

Also, it has a standard airbox and filter and has the rubber flaps still fitted. It has some interesting Japanese mods. I suspect the Japanese owner was a bit of a tinkerer. The rearsets are £500, the exhaust must have cost a packet, even the little indicators on the rear are nice (standard wont fit with the exhaust), but the jet kit was a few Yen too far. He should have stopped there :)

500 pound rearsets? what are they then.

[Harryredchow]

These bad boys http://www.moriwaki.co.jp/global/produc ... del=RVF400

I have a scuffed footpeg and gear selector and have been quoted £85 for the parts

[richyrd5]

Can I have first dibs on the pipe if you want to sell(will even get a standard system in the deal for you!)
or MAYBE! Swap you my micron carbon setup for it!

[Harryredchow]

I want to get the bike running right first and then I will consider going back to standard. Will let you know if I come to sell. The standard system would have to be mint though! :-)

[richyrd5]

Ok,, let me know chap.