82 GS650GLZ only runs at idle with choke 1/4 or more???

[Anonymous]

Subject kinda says it all. I was given a 1982 GS650GLZ and was told the carbs needed to be gone through. I've had the carbs off 7 or so times (honestly lost track at this point). Very efficient at it at this point so don't mind taking them off to try anything. I bought a Clymer manual and that was real helpful finding passages I didn't see the first few times I went through them, but I still can't get this thing to run.

It starts right up with the choke out and will warm up and idle for ever but as soon as I touch the throttle instant stall. It won't rev in the rpms at all. Any crack of the throttle and the engine dies, no misfires or anything it's just that as soon as the carbs start to open the engine dies out.

Can anyone help a brother out? thanks guy's. If I left any details that you need out just let me know.

-Brian

[DaveDanger]

Can guarantee that it's way lean and the choke is artificially enrichening it to make it capable of running at all. Sounds like maybe the floats are set too low, not enough fuel in the float bowls to allow for acceleration. I have no manuals on the 650's or I'd shoot you some specs.

[Anonymous]

thanks for the quick reply. I know that there all at the same level, and that there working needle and seat wise. But the level there at I don't know, they were all the same when I first took the carbs apart so I assumed that they were at the right level. That would be such a cool and easy fix. I'll look into that friday.

-Brian

[Anonymous]

any other sugestions, the bowls are all full when I take them apart and don't seem to set to low, they are actually full. Everything seems to be in working order, but this thing won't take any throtle.

-Brian

[flyingace]

Your plugs can help diagnosis here. When the bike has been running on choke, are they gas-wet, oil-fouled, carbon-fouled, dry?

[focus frenzy]

do you have the air box on??

if not, put it back on, the CV carbs don't work worth a diddly without the air box, or pods if jetted correctly.

[Anonymous]

flyingace: I need to recheck, but I think that they were dry. It's been a little while since I had it running.

focus frenzy: Yes, I have the airbox on with a brand new filter freshly oiled.

thanks.

-Brian

[gsBert]

let me get this straight, it starts on the choke but when you open the throttle ever so slightly it dies...

when warmed up, does it idle fine with the choke off?
does it idle at 3000 rpm with the choke on and 1000 with it off?

did you by any chance mess with the mixture screws? (air or fuel, dunno which carbs you have), by that i mean did you screw them all the way in?

if your bike doesnt idle with the choke off, your pilot circuit and idle screws arent adjusted right or clogged. opening the throttle leans out your mix to the point where combustion cant happen anymore.

once warmed up, can you crack the throttle a bit with the choke on? does it still die out?

we're talking about doing all this without any load on the engien right?
(stationary)

when you say opening the throttle, how much are you opening it? (less than 1/4)?

i'd like you to take the carbs apart and read me the number off your pilot jets, also make damned sure they're not clogged.
screw your mixture screws in and tell me how many turns it took until they were fully seated. (are they on the engien or airbox side on your carbs?)
take the mixture scerws out and make sure there are 2 washers in there a spring and an o-ring, and that the needle tip isnt blunt.
reassemble everything, and set teh mix screws where they were (if they were all the way in, set them 2 turns out to start with).

give me all my answers, and we'll take it from there.

[DimitriT]

Yep it sounds like the idle mix is set too lean. I ran into this when I rebuilt my carbs on an 82 550LZ. Start by getting them all 2 turns out from the fully down position. If that doesn't get you idling with no choke, add 1/2 turn out for each and then try again. If you don't have any clogged channels or jets it should run. Keep adding 1/2 turns until it does. Once you get them running you should vacuum sync and then lean out the idle mixture until its purring.

the choke circuit adds fuel to enrich the mixture but the nozzle is located in such a way that more fuel is not added when you open the throttle. the idle circuit has a venturi located to increase the flow with the throttle.

[flyingace]

Dry plugs on 1/4 choke tells me you aren't getting enough gas thru your carbs. That's different from running lean. Like it's just marginal enough to keep running on choke at idle, but any more throttle causes starvation. Things to check are plugged fuel filters, petcock (try using the prime position). Since you've retooled the carbs so many times, is it possible you mis-measured the float heights and it they are all too low?

You'll need to be 100% sure your carbs have an adequate supply of gas before you dig into them.