NC29 Jetting

[LUCAS]

I brought a Moriwaki system for my NC29 (N model) and it's really altered the jetting

Im using:

K&N air filter
Stage 1 Dynojet kit
Fuel silencer without baffle

Clip on needles 2nd position from top
112 main jets
Fuel mixture screw 2.25 turns out
Dynojet slide springs along with both holes drilled as per Dynojet instructions

Initially it felt like it was running out of steam top end and was slower than before. 116 main jets sorted that out thanks to advice from Graeme France

My main problem however is it runs terrible from 2000 to 4000 revs. Its very rough but then clears and pulls great above that. At that rev range I was going to look at fuel mixture screw settings and maybe pilot jets but wanted some advice beforehand as i know its going to very time consuming. The guy i bought it off used it for the Manx TT and club racing but he hasn't respond to my email.

Any help would be really appreciated. Thanks

[royster81]

speak with graeme again and maybe throw him some money for the advice,he's already helped you once, no doubt he's seen this before and knows how to fix it but isn't going to do the work for free, you can't blame the fella !

[Marcus127nc29]

put 100.212394857562829383479023028743 main jet in and 1/2 a turn out on carb 1, 1 turn out on carb 2, 1.1/2 on carb 3, 2turn's carb 4 and do the same to the needles and run it on water with jelly mix honey and put a old jumper in the air box

[sa.racing]

Is this problem happening at full or part throttle?

[LUCAS]

speak with graeme again and maybe throw him some money for the advice,he's already helped you once, no doubt he's seen this before and knows how to fix it but isn't going to do the work for free, you can't blame the fella !

Yeah Graeme is always good with advice. To be honest I was looking at getting his ram air setup and one of his systems. At least it's a tried and tested setup so there could be a fair bit of money coming his way lol

[LUCAS]

Is this problem happening at full or part throttle?

it's happening at minimum throttle opening - as I roll the throttle on.

[LUCAS]

Ok so spent way too long trying to progress with this problem today

Wound the fuel mixture screws in 1/2 a turn (to 1 and 3/4 turns out) and it cleared the rough spot which was 2000 to 4000 revs to somewhere in the region of upper 2000 revs to 4000.

Wound them in a further 1/4 turn (to 1 and 1/2 turns out) and its around 3000 to 4000 revs now. Still annoying the heck out of me but even more now after riding my brothers NC29 which has GF system, GF ram air and HRC CDI. Its fuelled perfectly so may bite the bullet and go for a known good setup.... now wheres my credit card

[Waza4]

Pilots on 2 turns
Could try raising the needle by dropping the clip 1 notch.

[LUCAS]

Pilots on 2 turns
Could try raising the needle by dropping the clip 1 notch.

I tried raising the needle last weekend and it made it run really rough up to around 6000 revs. I tried lowering the needle (clip on position 1) and it was very very fractionally better which gave me the impression it was running rich low down. It was then altered back to position 2 as per the Dynojet setup.

I haven't actually looked at the differences between the standard needles and Dynojet's properly.

The original slide springs have a lower number of winds on them but they both feel similar in strength. They are the same length.

I wish i had my own dyno £45 for one run at the local dyno is a bit much in my eyes for 15 minutes max. Saying that it would cut my hours down massively!

[Waza4]

Its still rich with the needle at its lowest (top clip).Sounds like your fuel level needs dropping.
How many miles have your carbs done?