Carb Jetting Questions

[Legend]

I am wondering if anyone has a starting point for me to begin with in jetting my carbs,

I am running open pipes and K&N Pod filters, if anyone has worked though this it would be much appreciated, I have had the carbs off 15 times in the last few weeks just trying to get it right, and still not having much luck.

Thanks in advance for any help.

81 GS 1000G

[almarconi]

What year and model bike do you have??

[Legend]

Sorry, Duh,

81 GS1000G

[almarconi]

Probably the easiest route is to get a dynojet stage 3 kit for your bike. It will have the adjustable needles, main jets and other bits to get your bike working properly.

[TheCafeKid]

Probably the easiest route is to get a dynojet stage 3 kit for your bike. It will have the adjustable needles, main jets and other bits to get your bike working properly.

Having just gone thru the same headache on my GS1100ES, I must concour. I have hand jetted bikes in the past, namely ones with mechanical carbs...but since your bike, like my 1100, has vaccum carbs, I would suggest spending the 120 or so bucks and get the jet kit. I fought and fought with my bike trying to jet it by hand, and finally broke down and installed a jet kit. Took me an hour, and it was running like a champ. I will NEVER EVER attempt to hand jet a set of vaccum carbs again if a jet kit is made for it...

[almarconi]

Take a look at this article, very informative..

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html

[Legend]

Thanx for the info,

CafeKid- do you recall the sizes and settings for your jets and needles?
did you have to replace your idle jet (not sure if that is the right name for it, the one under the rubber boot)

I have jumped to a 170 main jet and seem to have good high end pull, but have sluggish response through the midrange. with the occaisional backfire.

[salty_monk]

You need to put a bush in the main air jet to make it much smaller (the same size as the 16v BS34 carbs in fact (not the replaceable one... the one the other side) with the 1000G plus the needle has loads more taper on it. I am using a DJ 170 I think. That's about a 165 Mikuni though someone will be along to tell you the 0.9543 or whatever the divisional is between the two shortly....
No change to the Emulsion tubes or pilot circuit except to wind the screws out to about 2.5/3 turns.
You also need to drill the slides with whatever drill size DJ use.

I think you might be able to work it out with a bush in the air jet... Otherwise you need to go a lot fatter on the emulsion tube...

The kit is very simple for $100! I would just go with that personally.

Dan

[Guest]

Are you talking shrubbery in the air jet?

[salty_monk]

Well "bush" has 3 meanings in English... the one you picked & the other one are definitely no good for carbs so it must be a small bit of brass with a hole in it...

[Guest]

I got your drift. Had to jest
With a 170 main maybe he has a DJ ket.
If not get one!

[salty_monk]

What's that magic DJ to MK conversion number again??

[Guest]

.9375

[salty_monk]

I just put it in a spreadsheet to do the sums if anyone wants it...

Dan