Advice on carb setup

[scottsgs]

Hi all,

Well I am really banging my head this time. I finally have the old GS 850G leak free, however, I have a pesky problem of the engine hanging at about 1500 rpm after you twist to about 2500 or so. I have used contact cleaner and sprayed all the areas prone to vacuum leaks and nothing. The air cleaner looks fine and the carbs were running great prior to this last attempt to fix a leaking base gasket.

So here's my question; I used the Radio Shack washer trick to shim the needles and I went 2.5 turns CCW on the mixture screws. I just recently went through my valves and lapped all of them. Should I put the needles back to stock? Could that cause the engine speed to hang up?

Thanks,

Scott

P.S. I am running a V&H megaphone exhaust

[Steve]

OK, it's an 850.

What year?

The '79s had different carbs, and would require different solutions.

.

[Octain]

What year 850?
Can ya adjust the idle screw?

[scottsgs]

it's an 81

[Dave8338]

it's an 81

CV carbs. When you last went through the carbs, did you do the o-rings behind the intake rubbers? If so, which style of air filter are you running...foam/oil OR paper filter? 2.5 out on the air screws "may" be slightly lean.

What say you...

[scottsgs]

I'm using foam/ oil for the filter. I started at 1.5 out on the screws

[Dave8338]

I'm using foam/ oil for the filter. I started at 1.5 out on the screws

How about the o-rings between the intake rubbers and the head?

[scottsgs]

O-rings and intake rubbers were done just recently. I am going to try putting 1 more shim on each needle to lean it out just a bit. It's the only thing I can think of that would cause this. Everything else is fine.

[tkent02]

It's not the needles, they are not in play with a closed throttle. Mixture screw and pilot jets are doing the metering at that point. Back the screws out a little more, see if it helps. Better yet adjust them properly using the highest idle technique. Do you have the correct pilot jets installed? And are the pilot circuit's passages clean?

[Dave8338]

Bad spot in the throttle cable? I have one betweew 6,000-8,000 RPMs.
Started doing it after riding an entire day in the rain. Lubed and still no worky correctly. Just a thought.

[Octain]

I'm kinda with Dave here.. Sounds like something is stuck.
Will it idle down at all? In other words does the idle hang at 1500 rpm's all the time?
Again, have you adjusted the idle screw?