How much difference does 1 groove make?

[Bike_Nut]

Hi

Just had my bike dyno'd and its way to rich - from 4k to 6k its prob about 10:1 air:fuel ratio. Should I go 1 ring, 1ring minus spacer or 2 rings up on the needles? I really hate taking the carbs off so any experiences welcomed

PS Bakudan needles if that makes a difference.

[wullvfr]

did the guy who dyno'd the bike not give you any pointers?
what exhaust system is the bike running?



william

[Bike_Nut]

He said 1 maybe 2 grooves lol.

The bike has a yamamoto? system.

[wullvfr]

is it noticeable when you are out on the road?
like a flat spot?



william

[Cammo]

Although the bakudan needles are very different in design to keihin needles, a good starting point would be to get it to the same length/height as standard needles, or standard needles with an extra 0.5mm washer.

[Bike_Nut]

The bike ran quite well I thought, but if I went to a standard end can it did get a bit of a flat spot which made me suspect that it was still a bit rich. The plugs were also not white yet so I am almost inclined to go up 2 grooves to no2 groove

[CMSMJ1]

Yeah, agree - you need the needle to sit lower in the slide

[sa.racing]

Always do things one step at a time, Carberated bikes are very sensitive to any fueling changes and the bike will react differently to the needle positions, Maybe for better or worse but you wont know until you run it, Also when setting up needles you need to make sure the main jets are set right as well or this will give you a false reading

How much difference does 1 groove make?

Try it and then you will know the answer !
Let us know how you get on

[zimm]

dont bakudan needles have to be run with bakudan jets ?

assuming your main jets are correct (type and size) and the topend is fine, i'll stick my neck out here and say drop them 2 grooves.. it'll be a more pronounced change in the fuelling and easier to feel.. if its too far it'll be obvious, and the answer will be to go back up 1..

in my experience (especially when learning this stuff first time round) going 1 step at a time can lead to a lot of head scratching and dithering while you try to work out if its better or worse, or no different.

can needle height not be changed with the carbs in situ on an NC ?

[RVFJE]

You can adjust needles without taking the carbs off!