Are my carbs missing something!?

[madmike]

My carbs and fuelling etc. are ok at the moment but as some of you may know I'm still trying to perfect it. Adjusting my fuel/air mixture screws. I've been considering a new air filter, might help things A bit, But something I have noticed a few times in the microfiche and just recently online...

My carbs don't have the trumpets on the air intakes but THESE! spare set on the bay do! and the pic in the microfiche does too...

Will this effect things?

[fran9r]

You mean the silver velocity stacks?

If yours has none, then yes that would affect the power delivery. The 2 long and 2 short are used to try to get the best of both worlds -top end and midrange.

[madmike]

Ah... well, i'll get some ordered when I get back from anglesey,

Been thinking its running quite rich as it only requires a small amount of choke to start and run so when its quite cold I can't put the choke on anymore because it just floods and wont start. I thought the air/fuel mix screws might be out a bit but after reading that banoffee felt his NC30 was running rich so he put a K&N filter in and it sorted things I've just odered one, should be here before anglesey!

[fran9r]

Ah... well, i'll get some ordered when I get back from anglesey,

Been thinking its running quite rich as it only requires a small amount of choke to start and run so when its quite cold I can't put the choke on anymore because it just floods and wont start. I thought the air/fuel mix screws might be out a bit but after reading that banoffee felt his NC30 was running rich so he put a K&N filter in and it sorted things I've just odered one, should be here before anglesey!

That will only sort it if it's been re-jetted to suit a K & N, which has then been removed.

Usually rich running with an older bike is wear in the needle and needle jets. OEMs -Mikuni's they are usually replacable...Keihins, unlikely.

[lorenzo]

I don't think that the stacks will help a great deal in terms of things like cold starting Mike, but they should smooth things out in terms of pick-up once you're underway I'd have thought. It'd be interesting to find out what's what. Personally, I'd get the stacks, get a new air filter and then nip the bike down to runcorn for a dyno run, just so see what your air/fuel is doing at various points. That way you know with 100% certainty where you stand and can tweak stuff from there, rather than just basing it on guesswork based on how easily it starts, which could mean any number of things.

[madmike]

been thinking about taking it to a dyno center. Is it expensive to get it set up properly?

[banoffee]

I'd jetted mine (NC30) somewhat 'enthusiastically' for just a can so a K&N was something I wanted to try as easier than taking carbs apart again to fit slightly smaller mains. Seems to have worked a treat for me but that's why.

[lorenzo]

been thinking about taking it to a dyno center. Is it expensive to get it set up properly?

A pukka set-up thing would be about £100 at dynopro, down the road form you, but you could just do an air/fuel run for less than £20 I'd guess. I know they did a limited number of runs for £5 at one point, selling them on ebay. They'll firstly tell you what sort of power you're putting out, but most importantly, they'll give you a full plot of how it's fuelling and at what revs it's doing what. You can then suss out if you want bigger or smaller mains, or if you want to raise or lower the needles. Obviously, if it's fuelling well then you know it's not a problem with jets etc and there's issues elsewhere.