main jets: small round flat or large round flat

[elbandtioCA]

so this is what I'm doing at the moment:

...trying to fix a jetting issue (too rich, I'm going to put it to the same settings that other people with the same components have posted on that great jetting post)

but the jets that I ordered (n102.221, 6mm diameter) are on the left while the one that is in the bike is on the right (n100.601?, 8mm diameter). 


i really thought that i looked up the right jet size online... well, for all that i can tell, the small round jets have the same threading and jet opening as the large round--does somebody know if there's any reason why i can't use the smaller ones in the bandit carb?  or do i have to send them back and order the larger kind?

[Banditmax]

I think small round are keihin large round mikuni and they do have different sized holes in them for the same "jet size".

[interfuse]

As long as the have the same threading and the correcting hole diameter you're fine... I've used both the bigger and smaller style jets before.

[interfuse]

PS why are you going up a jet size to solve a richness problem?

Here's a good read.
http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

[elbandtioCA]

i'm not going up a size, i'm going down.  the guy who rebuilt them went to put the stock jets back in, but he didn't hav 102.5 so he put in 105.  he was using the stock needles.  but when the bike was too lean, presumably because of the exhaust, he swapped in the factory pro needles which the PO had.  the bike ran, but not great--it has had some rich symptoms.  so i'm going down in size to what a few other people with factory pro/yosh exhaust have posted on here--97.5/3rd position

[elbandtioCA]

the carb fun continues...of course something else came up...does the b4 carb have an o-ring under the pilot/mixture screw?  i was reading online about cleaning a similar mikuni carb and theirs has an o-ring there.  but i can't seem to find one on my unit.  i've been having idle problems so i'm checking out the pilot jet and mixture screws.  i also noticed that when all of the screws are all the way in, and i look into the manifold, the tip of one of the mixture screws stick up much more than others.  should i set it level with the other three and treat this as the "0" position?

[tomacGTi]

There should be o-rings and washers under the mixture adjustment screws. They do make a difference in your idle with them in place.

The Bandit fische doesn't show it but if you go under a gs500 (they have the same carbs) you can get them there.

[elbandtioCA]

are the o-rings and washers under the springs?

[tomacGTi]

The order is :

-mixture screw
-washer
-o-ring

[Banditmax]

The order is :

-mixture screw
-washer
-o-ring

-mixture screw
spring
-washer
-o-ring
you missed the spring tomac

[tomacGTi]

Whoops!!

[gsxr400 racer]