1983 gs750es fuel line help

[james22]

Hello fellow members btw im new here and wondered if someone can help i need to know how the fuel lines run on a 1983 gs750es i just bought this bike really cheap and im in the process of getting it running and eventually restore and ride the bike can any plz help me im stumped the bike starts with a little starting fluid but isnt getting gas so im thinking i got the lines messed up or im missing a vacuum line or something if someone can explain to me or maybe have a diagram that would be very helpful thanks and hope to chat or possibly help out another member bye for now and thanks....:-D

[kingofvenus]

Smaller fitting on the back side of the petcock is the vacuum line and go'es to fitting on upper front (front of bike) one on carbs. Will gas flow out of petcock when it is on the prime setting? (pri on petcock) Diaphram plunger in petcock could be stuck if bike has been sitting for awhile.

[DMPLATT]

'83 750ED is the same setup.

The Barb between #1 & 2 is the Petcock/Vac hose. The one between 3 & 4 is the main fuel line. The Main fuel line should be larger diameter than the vac hose.

Coming from Memory, I "Think" I had an additional barb off of # 4 that was a vent hose.

[james22]

thnx alot is that ur bike in ur profile pic if so i have the same exact one ya it has been sitting for awile and i thought too it wouldnt hurt to get a new petcock i just got it in today so im gonna change it to see if that was the problem will give feedback myfreind and thnx alot once again...

[DMPLATT]

That's my bike. Actually it's my brother's bike now.

Good Luck.

How long has it been sitting? Those carbs are a Muther to get out and in with that stock airbox.

[DMPLATT]

Oh, 1 thing you can try is disconnect the fuel line at the Petcock and hook up a piece of scrap hose. Put the other end in a container and crank the bike. I "Think" by cranking should get enough vacuum to get the gas flowing.
Also, the petcocks are equiped with a Prime. This shouldn allow gas to flow gravity style. If fuel is flowing either way, sounds like floats.........

[james22]

thnx for the info dave the carbs havent been rebuilt for some time i dont think...im gonna try rebuilding them but i need a good diagram or manual on mukuni carbsagain thnx bud...:-D

[DMPLATT]

http://www.thegsresources.com/files/vm_carb_rebuild.pdf

This is what I used. :-D

[fgh]

http://www.thegsresources.com/files/vm_carb_rebuild.pdf

This is what I used. :-D

An 83 GS750ES has CV carbs.

[koolaid_kid]

Here is one on rebuilding the Mikuni CV carbs.

https://www.sbtontheweb.com/pdfs/mikunisbn.pdf

Here is one on tuning the Mikuni CV carbs.

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html