vm carbs

[tconroy]

This forum needs a "how to" clean up series on vm carbs.Ive never done it before and the clymers manual doesnt help much on these.How many turns do you back the jets out and so forth.

[earlfor]

On a 79 750 you would want to turn out the fuel pilot screw between 1 and 1 1/2 turns. Mine ran best with them out 1 1/4 turns. I set the pilot air screws to 2 turns out. 1 1/2 to 2 turns out is the normal range.
(assuming you have stock airbox with filter and have stock exhaust)
Earl

This forum needs a "how to" clean up series on vm carbs.Ive never done it before and the clymers manual doesnt help much on these.How many turns do you back the jets out and so forth.

[wolfie]

Try this: http://thegsresources.com/files/vm_carb_rebuild.pdf

It's under technical on the home page. It wasn't quite as intuitive as the BS carb cleanup series, but it's a whole heap better than the manual.
If you haven't already taken them apart, GENTLY turn the screws in till they stop while counting the turns and record them for each individual carb. There is probably a scratch on the housing indicating where the factory setting was.

[earlfor]

The factory settings were quite lean. I wouldnt advise duplicating their settings.

Earl

Try this: http://thegsresources.com/files/vm_carb_rebuild.pdf

It's under technical on the home page. It wasn't quite as intuitive as the BS carb cleanup series, but it's a whole heap better than the manual.
If you haven't already taken them apart, GENTLY turn the screws in till they stop while counting the turns and record them for each individual carb. There is probably a scratch on the housing indicating where the factory setting was.

[wiredgeorge]

I very much dislike giving advice for the GS750 VM26 carbs. They have both a pilot fuel mixture screw and air screws as have been already mentioned. Problem is, Suzuki over jetted the pilot ciruit (idle) on the earliest by using a huge slide cut out and equally huge pilot jet (78 first year for the GS750?)... over the next couple years, the pilot circuit got progressively leaner. The last few years of the 750 VM26 and I think the pilot circuit was too lean.

I don't think one answer would fit all situations. If you had the first 750 made, your slide cut out would be 2.5 and the pilot jet #25. If you had the last, 1.5 cut out and #15 pilot jet. Tuning WILL be different. FWIW: It is easier to tune the later models than the earlier IMHO.

[earlfor]

Additionally, I have found that even identical models for the same year will not tune to exactly the same settings. At best, proven settings for one bike are a good starting place for another.

Earl

I very much dislike giving advice for the GS750 VM26 carbs. They have both a pilot fuel mixture screw and air screws as have been already mentioned. Problem is, Suzuki over jetted the pilot ciruit (idle) on the earliest by using a huge slide cut out and equally huge pilot jet (78 first year for the GS750?)... over the next couple years, the pilot circuit got progressively leaner. The last few years of the 750 VM26 and I think the pilot circuit was too lean.

I don't think one answer would fit all situations. If you had the first 750 made, your slide cut out would be 2.5 and the pilot jet #25. If you had the last, 1.5 cut out and #15 pilot jet. Tuning WILL be different. FWIW: It is easier to tune the later models than the earlier IMHO.

[tconroy]

Thanks wolfie thats just what I need!