34 tm Mikuni carb help

[nastyracing]

Who can shed some knowledge on these carbs ... First time im messing with them. Bike doesn't seem to want to run in any other needle position other then the first clip position. There is a QQ nozel in there . Started with 50 pilots which were to big for my application. Spoke with sudco they don't stock a leaner needle it's been discontinued . Is there a leaner nozel then QQ . It just bothers me that needle wants to be in leanest clip position. Someone with some experience please chime in. Also they are set up for gas

[fastbanshee8]

The Q0 is the leanest one.  I have the same carbs, but I'm on notch 4 to fatten up the mid-range.  What mods do you have done?

[dirtydownunder]

What ya mods n elevation ?
If i remember correctly 389q2 is the dump tube that comes in them, the 389q0 is leaner but unsure if there is a leaner dump out there. Q2 and q0 both worked for me, the q0 was a bit crisper but neither were a problem.

I run a 270 main in my with 50 pilot (don't think i stuck a lean pilot in) either way it wasn't a problem.
I run the stock needle on the leanest clip. bike runs awesome.

My biggest issue was the main jet, i started at 350 and it would run like shit and splutter.

This is with ported serval shearer pipes n these carbs. At sea level and 70f temps.

[sheerider11]

Stock stroke long rod. OG rockets. Vf4 pods I can't remember who ported it tho. Possibly an old rdz set up. The Bike crackles and sputters once the revs start to catch up. It'll pull down low, then instantly break up and run like shit.

[nastyracing]

420 stock stroke long rod. R2 pipes vf4 reeds , 5 degrees timing . I can get it to run strong up stairs but make horrible low end With a 50 pilot 350 main. With the smaller pilot 45 300 main in it makes strong low end but breaks up around 3/4 throttle. I have tried every single Jett ranging from 300-430 mains with both pilots and no luck. Tried every single clip position also with no luck other then first position . Just not to familiar with these carbs and "nozels" guessing my next step would be leaner nozel and that being a qo

[dirtydownunder]

i wouldnt be surprised if ya had to lean the main out more.

 

try the q0 as well but try some leaner mains, but keep an eye on the plugs.

 

also check your plug caps (resistance) cut a bit off the lead before you screw cap on.

check coil and pickup resistances n gaps n all that crap

[nastyracing]

It has new plug boots on it and everything else test out good . I did have smaller pilots In it 45s and 300 mains that I did plug chop in my opinion the ring it left looked lean. Bike pulled great 1-4 th gear sluggish in 5th and 6th felt even worst. I figured lean on main stepped it up to a 320 chopped it again plug looked lean imo. First time ever tuning these carbs , I'm sure there is a learning curve but they sure are a bitch. I'm almost tempted to jam a set of stock carbs on see if it does the same

[oldskool]

I run the needle that comes with the TM, The Q2 dump tube works the best for me on the banshee. ( Call Jeff at Fast). 4 mil cub with 45 pilot,320 main, 2nd clip from the top. air screw 1 turn out. pods,  sea level

Edited July 9, 2015 by oldskool