carb take 2
blackgpz at rochester.rr.com
Wed May 13 17:04:23 PDT 2009
>>Don't screw around with the pilot screws if it idled right before you
>>put the kit in. All the screws do is affect mixture up to about 1200 rpm
This is not correct. The pilot screws affect air:fuel up to about 4000 rpm
so it is important to get these right for good part-throttle cruise. You
must have the ability to adjust them so remove the plugs covering them as
outlined in the jet kit.
My recommendation FWIW:
Install 108 main jets (as you have an aftermarket exhaust, particularly the
large headpipe SS2r)
Do not change the pilot jets if you are keeping the stock airbox.
Set the pilot screws at 2 1/2 turns out from lightly bottomed. Your
adjustment range is 1 turn to 4 turns out. 2 1/2 turns out is the middle of
the range and a good starting point.
Drill the slides - be careful.
Put an e-clip in the second groove from the top of each needle. Put a shim
washer on top of that, then put another e-clip in the first groove to retain
the shim washer. This clip-shim-clip arrangement duplicates the thickness of
the "nailhead" of the stock needle so there will be no up & down play of the
needle in the slide when you put the white plastic retainer over it. Make
sure none of the "feet" of the white plastic retainer cover the slide lift
DO NOT install the kit supplied diaphragm springs. Reinstall the stock ones.
Put it back together and fire it up.
There are 3 circuits in the carburetor. The main jet is used in the 7000 to
redline RPM range, the needle controls the 4000-7000 rpm range and the pilot
screw from idle to about 4000 rpm. This is simplified a bit as there is some
overlap but for adjustment purposes, these are ranges each have the most
Start with the main jet. You must get this one right first. Take it out and
run it in the 7000 and up range. I know it's hard because of the speed
involved but what you are looking for is good throttle response, it pulls
hard and none to maybe a little blue smoke.
Next is the needle. Again, run it in the 4000-7000 rpm range. Again you are
looking for good throttle response, pulls hard and makes a good transition
through 7000 rpm.
Last is the pilot screws. What you are striving for is smooth running at a
steady 4000 rpm in second gear. If it runs smooth from the git-go, turn the
screws in a half turn at a time until it begins to surge and buck, then back
them out a half turn so you have the leanest setting the bike runs smoothly
at. If it surges from the start, back the screws out a half turn at a time
until it just goes away.
Everybody's bike is different and some adjustments may need to be made to
tune your particular bike. The above is a good starting point.
Steve in Western NY
'08 KLR 650
'08 Tuono Factory
"You Can't Fix Stupid", Ron White
----- Original Message -----
From: "andy burkard" <andyburkard at yahoo.com>
To: <annihilator1100 at hotmail.com>
Cc: <gpzlist at micapeak.com>
Sent: Wednesday, May 13, 2009 6:32 PM
Subject: RE: carb take 2
I just so happened to re-jet (to stock) this weekend.
I was running the dynojet stage 1 kit with a jardine full exhaust system,
and stock air box.
104 main jets
38 pilot jets (not included in the kit)
Clip in 2nd (from top) groove
1 shim above AND 1 shim below clip
Don't screw around with the pilot screws if it idled right before you
put the kit in. All the screws do is affect mixture up to about 1200 rpm or
If you are running pods, you'll have to play with the clip and shim
Jonathon Jay wrote:
> I know someone out there has the ideal settings for the jet kit, please
> someone chime in.
> Perhaps we could get it on the websit, I know this comes up a few times
> every year.
> I recall someone saying floats in a certain clip position. I don't have
> any clip position other than one. What makes my carbs differeny, perhaps
> I'm not looking in the right spot.
> What's The Difference Between Ignorance And Apathy?
> ~ I Don't Know And I Don't Care ~
> Hotmail® has a new way to see what's up with your friends.
More information about the GPZList