Think I'm going to order a wideband O2 sensor & gage...

srk468 · May 7, 2011

Motorcycle carbs I'm having some trouble understanding, seems like any direction I go is wrong, I have Sean's kit with the different springs & drilled slides but I just can't seem to find the sweet spot. 157.5 jets, needles on 3'rd clip from pointed end, and idle mixture screws 3 1/4 turns out, it runs ok but plugs look rich but the thing seemed to have a better top end charge with 165's in it, doesn't help that I'm getting used to the bike so its feeling slower & slower! LOL Give me a 4150 or 4500 Holley and I'm pretty good but I just can't seem to gain much performance out of this setup so I'm going to order a dynotune wideband kit to help me understand where I'm lean & where I'm fat, gonna spray the bike next year and the air/fuel will be really helpful there. Guess I should say something about the bike if anyone has any tips.

Niles, MI elevation 686'
94 max engine stock 8600 miles
Kerker 4 into 1 with 2.5" comp baffle
Dyna with limiter on 9500 advance curve #4
Morley kit with drilled slides & the springs that come in the kit
157.5 mains, needles on 3'rd clip from pointed end
mixture screws 3.25 turns out.

Don't get me wrong the bike runs well but I know there's more in it!

srk468 · May 7, 2011

http://www.dynotunenitrous.com/store/scripts/prodView.asp?idproduct=150

This is the one I'm thinking about getting, a friend has one on his turbo Busa and likes it alot. Also forgot to mention I'm shifting at 9000rpm

SpecOps13 · May 7, 2011

That appears to be a great unit at a great price...I wonder if anyone else here has already got one...

Dave

dkw0417 · May 7, 2011

I just put a Mark's 4-2 with a very similar carb setup and mine feels alittle weak as well. I am on the second clip from the blunt end with one shim, I guess that makes it 2.5. Was at just the second slip but had a mid range stumble, the shim took care of that. I plugs look good, tan and grey.

Let me know what you change if you get that gauge. I will probably need to go the same direction to get the power back. I have also run a couple of gas tanks through it this way and my mpg is actually worse, although that could be due to the enjoyment of the sound of the pipes.

srk468 · May 7, 2011

dkw0417 said:
I just put a Mark's 4-2 with a very similar carb setup and mine feels alittle weak as well. I am on the second clip from the blunt end with one shim, I guess that makes it 2.5. Was at just the second slip but had a mid range stumble, the shim took care of that. I plugs look good, tan and grey.

Let me know what you change if you get that gauge. I will probably need to go the same direction to get the power back. I have also run a couple of gas tanks through it this way and my mpg is actually worse, although that could be due to the enjoyment of the sound of the pipes.

I'm probably going to go back to the 160 jet and lean up on the needles some but I'm definitely getting this gauge kit, then I should be able to dial it in perfect.