1983 GS 550L carb confusion

[Guest]

Hey guys this is my first post... I'm working on a GS right now and It's really starting to get to me.

First off, when looking for carb diagrams (the carbs were given to me in a box, in old crusty pieces) I couldnt find any carburetors that matched what I had online. Searching for 1983 gs550 carbs brings up pictures of 4 separate carb bodies, where as mine are two mikuni's internally divided to 4 throttle valves. So finding diagrams is next to impossible.

But... My main issue is this. I have rebuilt them and cleaned them thoroughly. All jets are clear and all seals are replaced... the floats are in great shape too. however, I have not been able to connect the OG gas tank to it due to the inside being incredibly gross. The petcock is also clogged/rusted/crusty.

I've been gravity feeding the carb from a mini hanging fuel tank to try and get it started, with no luck. I can get it to run with ether for short periods of time, so I know it CAN run.

However the carb has two inlets, one main fuel inlet for the float bowls and then another single, tiny inlet infront of a throttle valve that I assume feeds vacuum to the petcock and gets everything going.

In order to get this guy running properly, what do I do? I've ordered a replacement tank and good condition petcock, will this fix my issue?

I understand that the petcock is vacuum operated BUT would that prevent the carb from starting the engine? theres fuel in the bowls, and spark from the coil... does the tiny inlet at the throttle valve need to be connected?

[JEEPRUSTY]

Is your air box connected? I can think o nothing in your setup that would prevent proper running.

You can go here to get the manual. Oh and plug the vacuum line.

http://members.dslextreme.com/users/bikecliff/

[GSX1000E]

Have you been plugging that vacuum line?

[OathCycles]

Have you been plugging that vacuum line?

I've tried plugged and unplugged!

[JEEPRUSTY]

Airbox installed? Choked plugs in place?

[tom203]

Probably clogged "choke" system. Try blocking carb throats with something (2 x 4 or extra hands) and crank it to see if you can create more vacuum behind throttle plates to pull up fuel into throats.
make sure plug wires are on right!

[OathCycles]

Probably clogged "choke" system. Try blocking carb throats with something (2 x 4 or extra hands) and crank it to see if you can create more vacuum behind throttle plates to pull up fuel into throats.
make sure plug wires are on right!

firing order could be off... plug wires are numbered but have aged badly and that plastic number is not readable.

[JEEPRUSTY]

airbox installed? Gonna answer a guy who runs one of these and who has cleaned the carbs or kow tow to generalists?

[OathCycles]

yes, nothing customized about the bike. Stock airbox and everything.

[JEEPRUSTY]

wow carbs is dirty still I would think

[OathCycles]

completely rebuilt. soaked in solvents, fine metal wire ran through all passages, compressed air ran through all passages.

[tom203]

completely rebuilt. soaked in solvents, fine metal wire ran through all passages, compressed air ran through all passages.

You know that little brass tube that sticks out of carb body and fits down into passage leading to fuel bowl bottom....try blowing gumout thru it and see if it shoots out into carb throat. Plus shoot gumout down fuel bowl passage to make sure it ain't blocked.

[OathCycles]

I'm going to clean the carbs out one more time, and then give up on this. I've literally done everything I can think of, short of buying brand new carbs for it.