More NC30 carb advice, pretty please!

[magg]

Is the air box standard and the air inlet ducting in place?

[b1hrider]

I'm waiting for some spares to arrive so i can try it with 115/118 jets. It pulls well at full throttle with the 118/120's, but till I've tried the smaller ones i don't know which gives the best power, and then i'll work from there again. I know 118/120 with standard airbox and race can should work, just on mine, it doesn't!

[b1hrider]

Yes, standard airbox and ducting in place. Tried it without airfilter in today cos jets not arrived yet, still too rich at part throttle. So def not cos airfilter clogged which I didn't think it was.
So on to carb removal and float check or adjust again.

[TommyTheGun]

Im down to 112s all round and still too rich mid range.

[b1hrider]

How's your top end though? If wide open throttle is fine and pulling strong, main jets should be right? Have you noticed any improvement or worsening of top end as you've gone down in main jet size? That needs to be tuned first, if thats not right, nothing else will be able to be sorted correctly.

[TommyTheGun]

Top end is good pulling really well. I had 118 and 115s in for first dyno then changed down to 112s for second and it improved it by a couple of hp. Going well low down too. I had a look at the element in my air filter tonight which i fitted in december and hasnt done many miles. Down the folds it there was loads of that yellow glass fibre stuff that is on the bottom of the petrol tank. I wasnt expecting it to be so bad wouldnt have been doing it any good at all! I have ordered the k&n filter to do the chrysler mod, its about the same price as a standard filter anyway plus its reusable. I have refitted the snorkel and made 2 holes in the bottom of the tray the snorkel points at so it can get fresh air into it rather than air in that space under the tank. Hopefully that will stop it sucking in the yellow fibres too. Next time its dynoed it could well need bigger jets again but they are easy to fit, just hope it helps the midrange.

[b1hrider]

I think the whole point of the tray is that it stops HOT air from being inducted, so drilling holes in it won't do it any good I don't think. All the air it pulls into that space is fresh, atmospheric pressure sees to that lol.The air it pulls from the holes you drill will be directly from behind the top rad i.e. very hot, hot air is not good for the fuel mix, which is why turbo engines make use of intercoolers, to cool down the air charge.
I'm frustrated that i've not sorted mine yet, but highly reluctant to deviate from the standard airbox setup which is known to work for most folk.

[magg]

b1hrider is correct, holes in the tray will allow hot radiator and engine air to flow into the airbox and adversely affect the fuel mixture. The HRC TT F3 kit does not modify this tray, only adds holes in the sides of the airbox to suppement the snorkle. Standard air inlet appears to work best.

[krisztian_andre]

I have the a similar problem with a standard bike plus a tyga system that it's very rich with 115/118 mains 11.6 A/F ratio at sea level and sorted carbs, standard everything.

[magg]

TommyThe Gun, your comment regarding worn needle jets and needles is worth investigating. Have known of cases were if these items are badly worn mid range richness has caused poor engine running. Also the part numbers for the OEM needles and needle jets are differnet between front and rear cylinder pairs. Might be work checking that needles and needle jets have not been mixed, you could also measure the needles and needle jets to see if there is any variation or better still try locating a new set to establish a base measurement.