mixture adjust

[gs850cmc]

Finally up and running stock 1980 GS850G (45k miles). Performed complete carb tear down and rebuild, replaced all o-rings, intake manifolds, air box manifolds. Had the bike since 2000. Now it starts w/o choke, it never did that before..very happy and it settles quickly down to 1000rpm. Thanks to all on this site for their tips and expertise. I have one minor concern, it seems that the pipes are coloring faster than they ever did before, in fact the pipes on this bike never colored at all, almost perfectly chromed. I preset air screws 2.25t turns from seated. Could this be my issue? Should I back them out a bit while striving for max idle. Thanks again, trying to attach a picture

[rapidray]

YES! Set the mixture screws with the engine idling to get the fastest idle on each carb. The mixture screws are the easiest circuit on the carbs to tune as the motor will "tell" you where it wants them. Ray.

[chef1366]

I would raise the needle a bit with washers to richen the needle circuit.

[gs850cmc]

Thanks for the tips,

I will first sync my carbs, I just received motion pro sync tool. Although it is running pretty good, I did not even bench sync so I think I will be able to get running even better after sync then do adjustments.

Will post on how things work out.

Thanks again.

Charlie

[alke46]

That's a beautiful bike. Brings back lots of memories. I had one nearly identical to that and like a dummy, I sold it after I got my Honda ST1100.

I just didn't like the high rpms on the highway and went to the Honda. Lower rpms and quiet as all get out.

Sold it in 1997 and sure would like to get it back today. Man I miss that girl.

[lilbilly]

YES! Set the mixture screws with the engine idling to get the fastest idle on each carb. The mixture screws are the easiest circuit on the carbs to tune as the motor will "tell" you where it wants them. Ray.

BassCliff has the instructions for the 'highest rpm' method on his website, this is what you are referring to right?

Also, for a newb like me - where are the mixture screws located? I know, I know...gotta learn sometime I guess.

[Steve]

This is on an 850, but they are almost all the same:


.

[lilbilly]

Thanks...

Follow up question - BassCliff's instructions say to do it with the tank off and an alternate fuel supply. Is there an easy way to rig a homemade fuel set up? What do you guys reccommend?

[BassCliff]

Hi,

The next time you pass by an auto wrecking yard, stop in and pick up an old windshield washer fluid tank.

Or, I use my regular tank with an extra length of fuel hose and a 5/16" brass barb connector/splicer thingy.



Remove the tank, set it on something solid near your bike (higher than the carbs), attach the extra length of fuel hose to the tank's petcock, use the connector to splice into the fuel line on the bike, set the petcock to prime, away you go.

Thank you for your indulgence,

BassCliff

[lilbilly]

Hi,

The next time you pass by an auto wrecking yard, stop in and pick up an old windshield washer fluid tank.


Thank you for your indulgence,

BassCliff

Good call...

If one doesn't have that available can a milk jug or other gallon size jug be used somehow?

[BassCliff]

Good call...

If one doesn't have that available can a milk jug or other gallon size jug be used somehow?

I edited in another, very cheap, solution.

Sure, you can use just about any bottle or jug that will hold gasoline safely. The trick is finding the right fitting for the fuel line.


Thank you for your indulgence,

BassCliff

[lilbilly]

Hi,

The next time you pass by an auto wrecking yard, stop in and pick up an old windshield washer fluid tank.

Or, I use my regular tank with an extra length of fuel hose and a 5/16" brass barb connector/splicer thingy.



Remove the tank, set it on something solid near your bike (higher than the carbs), attach the extra length of fuel hose to the tank's petcock, use the connector to splice into the fuel line on the bike, set the petcock to prime, away you go.

Thank you for your indulgence,

BassCliff

Okay, I see how this would be pretty simple.

Another () follow up question. You say set the petcock to prime - set it to prime for the entire time while doing the tuning?

[BassCliff]

Hi,

Yes, plug the vacuum line to the carb. Set the petcock to prime so that fuel will flow. The vacuum petcock will not flow fuel without vacuum applied. Setting the petcock to "Prime" allows fuel to flow via gravity.


Thank you for your indulgence,

BassCliff

[lilbilly]

Hi,

Yes, plug the vacuum line to the carb. Set the petcock to prime so that fuel will flow. The vacuum petcock will not flow fuel without vacuum applied. Setting the petcock to "Prime" allows fuel to flow via gravity.


Thank you for your indulgence,

BassCliff

Okay, now I'm definitely still lost - sorry for the sudden confusion, I'm not by my bike and I'm forgetting how it looks.

Vacuum line/fuel line are the same or different?

[Steve]

The vacuum line is smaller than the fuel line, both of them connect to the petcock.

When you remove the tank, the vacuum line will be a SERIOUS leak, so plug it with a golf tee or a Philips screwdriver. Extend your gas line from the tank to the bike, connect with the splicer.

NOTE: when you have your tank off the bike, don't put it much higher than the stock height, or you may overpower the float valves, changing the fuel level in the bowls.

.