Main Jets.

[javamotorsports]

Good morning,


I have a 1980 gs850L that someone cut the baffles out of the muffler the bike is still rideable but spudders a little. Does anyone know what size jets to put in it to correct this problem? I plan to replace the mufflers later on but really would like to get the spudder out of the bike to make it even more enjoyable to ride.


Thank you for any and all input.


Jason

[posplayr]

Good morning,


I have a 1980 gs850L that someone cut the baffles out of the muffler the bike is still rideable but spudders a little. Does anyone know what size jets to put in it to correct this problem? I plan to replace the mufflers later on but really would like to get the spudder out of the bike to make it even more enjoyable to ride.


Thank you for any and all input.


Jason

Stepping up one size on the main jets would probably help, but you would need to go back if you ever replaced the mufflers. You could look at your manual but you never know what someone else might have done so you should physically check what is in there now.

[BassCliff]

Hi,

You'll find a handy chart with stock carb specs here:

Suzuki GS Series Carb Specs

As Mr. posplayr suggests, you may have to experiment a little with jetting, and perhaps needle height, to get the desired performance. There are no hard and fast rules. Jetting as as much an art as a science.


Thank you for your indulgence,

BassCliff

[1_v8_merc]

You'll probably need to bump up 2 sizes.
(which is really nothing....considering these bikes are usually Lean from the factory, unless the 850's are some kind of black sheep and Rich?)

[javamotorsports]

thanks

How do you adjust the needle setting? I have seen photos of little notch in the needle to adjust it up or down. However mine does not have notches to raise it up or down. It runs so well now that I only need a little to make it perfect. Thanks again for the great information.

[javamotorsports]

thank you

Never mind I just looked at the chart sent to me. Thank so much.

[BassCliff]

Hi,

The CV carbs don't have adjustable needles. You have to use small washers to shim them in order to raise them a little. The procedure is described here: Shimming The Needle.

You can buy specialized adjustable needles for these carbs but they are usually part of a jet kit, i.e. Dynojet stage 1 or stage 3 kits.

Thank you for your indulgence,

BassCliff

[posplayr]

this might help in deciding whether a needle notch or a main step size or the combination is what you need

http://www.thegsresources.com/_forum/showthread.php?t=164565&highlight=AFR+info

[duaneage]

TheBigRed had the same problem with his 550T, PO punched the holes out the rear of the cans. He had to go up 2 sizes. He just recently replaced the mufflers and went back to stock. I understand both circumstances were good, only now the bike is much quieter.