Some carb help PLEASE :) 1983 GS850

[mortation]

I have a 1983 GS850 GLD and I rebuilt the carbs.

Now I need to know the settings. Badly.

All screws where tightened down.

The fuel/air screw was backed out 2.5 turns. (Thats the screw I had to drill the little plug out) on all four carbs.

I did a bench sync using a piece of wire. I.E. I adjusted the idle screws so all flaps on the engine side of the carbs opened at the same time.

I have a manometer but have not tried it yet.

Is this correct or am I missing something??????

 

[Steve]

That's a pretty good starting point.

Did you also verify the float heights?
When you did your bench sync, did you start with carb #3, then match all the others to it?
Then did you go back to verify that the settings did not change?

1) Get everything back together in the bike. You will need to also attach the stock airbox or pods.
The carbs will NOT run right without something on the intake side.

2) Don't forget to re-adjust the master idle speed control before starting the bike. After a bench sync, it might be too high. :shock:

3) Use the PRIME setting on the petcock (or a remote temporary tank, which makes it easier to do the gauge sync)
to put fuel in the float bowls.

4) Start the bike, but keep the kill switch handy in case it starts to run away from you. (See #2, above.)

5) Let us know how well it runs. \\/


.

 

[mortation]

That's a pretty good starting point.

Did you also verify the float heights?

Yes. Then took em apart and checked em again. They are all right.

When you did your bench sync, did you start with carb #3, then match all the others to it?

Yes.

Then did you go back to verify that the settings did not change?

Yes. And now I was going to do the balancers which should make everything 100% right?

1) Get everything back together in the bike. You will need to also attach the stock airbox or pods.
The carbs will NOT run right without something on the intake side.

Done. Using stock box with new air filter.

2) Don't forget to re-adjust the master idle speed control before starting the bike. After a bench sync, it might be too high. :shock:

Done

3) Use the PRIME setting on the petcock (or a remote temporary tank, which makes it easier to do the gauge sync)
to put fuel in the float bowls.

OK

4) Start the bike, but keep the kill switch handy in case it starts to run away from you. (See #2, above.)

OK

5) Let us know how well it runs. \\/
.

Like crap lol. How do I tune the fuel/air screw to know when its right? I thought the mano meter would do that but it looks like it is just for the idle.

I am gonna see if I can record this with the video camera and post it online.

 

[Nessism]

Did you replace the intake O-rings while the carbs were off?

 

[mortation]

I replaced all the O-rings and boots and air filter. Its running OK. I think I might just be being picky. I am gonna test drive it on the ****ty tires tomorrow and see how it goes.

 

[bwringer]

Only other things I can think of:

1) Did you plug the vacuum line on the #2 carb while the tank was off for syncing?

2) Does the air filter element have only the faintest whisper of oil coating it? If you soaked it, wash it out with detergent and hot water, dry overnight (or carefully with compressed air), and reinstall. There'll be a very slight film of oil remaining, which is all you need. Over-oiling is very common, and will make the bike run rich.

3) Did you seal the airbox covers on BOTH sides with foam weatherstripping? This is VERY VERY VERY EXTREMELY important. You also need a layer of foam on the top of the air filter cage to make sure the air filter seals against the top of the airbox (once the weatherstripping is in place, coat the top layer with a thin layer of grease so it will slide into the airbox.) Basically, air should only be able to get in via the snorkel on the back of the airbox and the vent holes at the bottom, and it should not be able to bypass the air filter at all.

4) After a short test ride, what do the plugs look like?

 

[bwringer]

The air screws only have a slight effect on idle and off-idle transition -- they don't have anything to do with how the bike runs above 1,500 rpm or so.

And personally, I find that it's impossible to hear or feel any differences at all when you twiddle one air screw at a time while the bike is idling (assuming everything else is working as it should). Despite 10 years as a professional musician, I apparently don't have a fine enough ear to hear the difference...

You're supposed to tune these screws individually, but I just set them all the same and test-ride to see if the off-idle transition is smooth. If not, I adjust in 1/4 turn increments until I'm happy. 2 or 2.5 turns is a good starting point. With the right small screwdriver and an assistant, you can quickly remove the tank bolts, raise the tank slightly, and twiddle the idle screws without removing the tank.