Carb Problems! :-(

[jakeolsen]

Well today I finally got my carb rebuild kits in the mail. I took my time and reassembled the carbs according to the guide from bike cliff. I put the air mixture screw to 1 1/2 turns out, and put the carbs back on the bike. The carbs were soaked in berrymans for a few days before, and they are thoroughly clean. I am getting spark, and gas is flowing from the petcock. I can't get it to start though. It doesn't even sound like it is igniting even the most finite amount of fuel. I am not leaking fuel anywhere, so I expecting the plugs to be soaked after many tries at starting without success. They aren't though. What could I be doing wrong?

[teet]

Well today I finally got my carb rebuild kits in the mail. I took my time and reassembled the carbs according to the guide from bike cliff. I put the air mixture screw to 1 1/2 turns out, and put the carbs back on the bike. The carbs were soaked in berrymans for a few days before, and they are thoroughly clean. I am getting spark, and gas is flowing from the petcock. I can't get it to start though. It doesn't even sound like it is igniting even the most finite amount of fuel. I am not leaking fuel anywhere, so I expecting the plugs to be soaked after many tries at starting without success. They aren't though. What could I be doing wrong?

Are you sure your petcock is flowing? Are the bowls full? Are you priming the carbs? I would double and triple check your fuel line, filter if you have one, and length and routing of the fuel line. Mine was too long and swooping when I replaced it and I couldn't even get the bowls to fill.

Good luck,

Jeff (teet)

[jakeolsen]

I don't have prime on ym petcock. Just Res to the left and on is down

[81gs1100]

Are you trying to start the bike without the airbox installed?

I know with factory installed jets that were in my bike made is a pain in the ass to start without assistance from a starting fluid without the airbox.

[jakeolsen]

I have the airbox installed, and the filter as well.

[81gs1100]

There could be a lot of things that may be the problem.

Did you set the floats to proper hieght, from the proper location on the float?

Loosen the drain bolt on the float bowls and check for proper filling.

Check the vent tubes to make sure they are free flowing and not pinched or capped off.

Have you tried giving a shot of carb cleaner into the box to see if you can get some action?

[kparkfan]

Dont all petcocks have a prime position? I know on my petcock I have prime and on.

[jakeolsen]

My bowls are all nice and full, and not over flowing. Could I have a vacuum problem somewhere? What about the hose that goes to the top of the engine? If that got disconnected would it cause a problem?

[jakeolsen]

Just as an aside. On the part of the carb that goes to the intake there is a screw on top and a jet on the bottom. I did the screw on top to 1 1/2 turns out from seated. The one on the face(jet) i screwed all the way in... is this right?

[jakeolsen]

Oh, BTW here are my carb specs. I'm not sure I understand them though. Does this say my air mixture screw should be 3.5 turns out?


GS550 (80-82) the specs are for the CV's

idle r/min 1100-+/-100r/min
carb mik bs32ss (4 seprate carbs)
id no 47160 (us) 47170 (can)
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-0.5 (0.20 +/-0.04)
main jet #92.5
main air jet 1.6
jet needle (4bel2 us model) (5f42-3rd notch canadian adjusable needle)
needle jet x-6
pilot jet #40
throttle valve #135
by pass (0.9, 0.7, 0.7 us model) (1.0,0.8,0.8 canadian)
pilot outlet 0.7
valve seat 2.0
starter jet #35
pilot screw 3.5 turns back (mixture screw)
pilot air jet (us model #150) (#120 canadian)

[dlanes]

What you been using the choke at? The reason I ask is because after I rebuilt my carbs I only have to pull the choke up half way and it will start.

[tlepac]

Dont all petcocks have a prime position? I know on my petcock I have prime and on.

My 79 750L doesn't have prime on it---Only the on and reserve.

[jakeolsen]

I was giving it full choke.

[jakeolsen]

It is just weird because I have full floats. I have spark. I have very clean carbs freshly rebuilt, and yet I am getting no rpm spike when I try to start.

[Steve]

Are you moving the throttle?

Don't.

It's kinda bad when we don't find out until post #10 what bike you are talking about.
Just another reason for the common request to put your bike in a signature line and your location in your profile.
There just might be somebody near you that can come over and help.

Yes, your idle mixture adjustment screws will likely need to be turned out some more. Not sure about 3.5 turns, though, but the 550 might actually need that. Most of us with larger bikes will start with the screws between 2 and 3 turns out, then fine-tune from there.

The 'choke' mechanism on these carbs does not choke the intake like the car carburetors used to back in the day. It is actually an 'enrichening' system, hence my use of quote marks when mentioning the 'choke'. When activated, it uses the relatively high engine vacuum to pull fuel and air through special ports that feed a very rich mixture. If you open the throttle at all, you destroy that vacuum and you will not be sucking the rich mixture that you want. Once you get your engine running, you will get a feel for just how much 'choke' to apply to start the engine, then you regulate engine speed by adjusting your knob or lever, whichever you have. When everything is properly adjusted and running well, you should not have to run on 'choke' for more than 30 seconds to a minute, or about the time it takes to put on your helmet, then get into second gear.

.