Carb Jetting

As evidenced in past RMD threads, I'm not a genius at carb
jetting. My bike appears to be jetted perfectly for the conditions
here though. No blubbering anywhere in the throttle range. Our
elevation is around 600' above sea level.

That said, I realize that at 5,100'+ I'll likely need some changes
for Baumgartner. My carb is the Mikuni VM38SS. The stock settings (I'm
not sure what the current settings are because I never wrote them down
and the bike's in storage right now) are:

Float level: 10.9-11.9 mm
Needle clip: 2nd groove
Jet needle: 6FJ40
Main jet: 320
Needle jet: R-0
Pilot jet: 50
Slide cutaway: 4.0

So can you guys tell me the most likely components needed to rejet
for the higher altitude? I mean, would I start with *higher* number
jets? Are the main and pilot jets the most common switches for
re-jetting (along with needle clip adjustment)? How many different
sizes should I buy? I just wanna be prepared without buying a lot of
unnecessary stuff... like what are the odds of needing a new slide
cutaway, for example?

Thanks, kids.



CrashTestDummy - '85 RM-250
f.j.bradfordREMOVE.DeleteThis@verizon.net

On Sat, 20 May 2006 17:46:18 GMT, CrashTestDummy
<f.j.bradfordREMOVE.TakeThisOut@verizon.net> wrote:

>
>
> As evidenced in past RMD threads, I'm not a genius at carb
>jetting. My bike appears to be jetted perfectly for the conditions
>here though. No blubbering anywhere in the throttle range. Our
>elevation is around 600' above sea level.
>
> That said, I realize that at 5,100'+ I'll likely need some changes
>for Baumgartner. My carb is the Mikuni VM38SS. The stock settings (I'm
>not sure what the current settings are because I never wrote them down
>and the bike's in storage right now) are:
>
>Float level: 10.9-11.9 mm
>Needle clip: 2nd groove
>Jet needle: 6FJ40
>Main jet: 320
>Needle jet: R-0
>Pilot jet: 50
>Slide cutaway: 4.0
>
> So can you guys tell me the most likely components needed to rejet
>for the higher altitude? I mean, would I start with *higher* number
>jets? Are the main and pilot jets the most common switches for
>re-jetting (along with needle clip adjustment)? How many different
>sizes should I buy? I just wanna be prepared without buying a lot of
>unnecessary stuff... like what are the odds of needing a new slide
>cutaway, for example?
>
> Thanks, kids.
>
>
>
>CrashTestDummy - '85 RM-250
>f.j.bradfordREMOVE@verizon.net

Open you carb and determine what you currently have in there.

Bring the next 3 leaner main jets and the next 2 leaner pilots. That
should cover you. I would put in a main jet that is 2 sizes leaner
and a pilot that is 1 size leaner before even loading up to go.

Mike Baxter --------------- "All GasGas, All The Time"

2005 GasGas EC300, 2000 GasGas EC300, 1997 GasGas JXT270