'81 GS750 TSCC Carb Issues

[Anonymous]

I Recently Purchased my first motorcycle, a 1981 GS750L from a friend of a friend. The Bike had been sitting for a year or two and was running when he put it away. Before trying to start it I topped off the oil and popped in a new battery, and cleaned the plugs which were black.

Well, it wouldnt start at first so I removed the air box, sprayed in some starter fluid, and she fired right up, but only to burn of the starter fluid. I pulled a couple of plugs and they were wet with fuel, but it would not light with a bic cigarette lighter. It was about this time that i noticed a pool of fuel underneath the beast.

I figured that some or all of the needle valves were gummed up, so I pulled the carbs and sure enough, 2 of the 4 needle valves were sticky, I freed them up with some carb cleaner and reinstalled the carbs tank, this time with fresh fuel in the tank.

The bike still didnt run, and when i pulled the plugs again they were totally dry. After Determining that there was fuel in all the float bowls, I pulled the Carbs off again and cleaned the main jets after reading about them in the clymer manual that came with the bike (I'm kindof new to this whole carburation thing, I mostly work on my '92 eagle talon with Multi Port Fuel Injection).

The needle valves, main jets, needle jets and jet needles seem to flow freely and the CV assemblies move up and down alright even though i never pulled the top covers off of the carbs. Is there anything else i should check/do before reinstalling the carbs? Basically I am trying to avoid a total rebuild at all costs. Thanks for all your help!

-Rob

[Billy Ricks]

You need to do a total carb cleaning. When old fuel dries up in the bowls a gummy varnish is left behind that clogs up the different jet circuits. If you look on the homepage you will fing a carb cleanup section. Follow it and you should be able to get your problem sorted out.

[Anonymous]

It seems as though most of the buildup in the carb is a fine particulate, It almost looks like rust when it comes out of the passages, but it comes out without much persuasion and levaes the passageway pretty clean (the needle valves freed right up when I cleaned them), maybe Im just avoiding the imminent, but im kind of nervous as I have never had a carb that far apart before. If and when I do rebuild my carbs is it necessary to 'count turns' when removing the pilot jet and idle air screw? Also, I've heard that using something to poke out parts of a carb can be vey bad as it can enlarge the diameters of the many orifices of the carb and really screw everything up what do you guys think?

[moto_dan]

It seems as though most of the buildup in the carb is a fine particulate, It almost looks like rust when it comes out of the passages, but it comes out without much persuasion and levaes the passageway pretty clean (the needle valves freed right up when I cleaned them), maybe Im just avoiding the imminent, but im kind of nervous as I have never had a carb that far apart before. If and when I do rebuild my carbs is it necessary to 'count turns' when removing the pilot jet and idle air screw? Also, I've heard that using something to poke out parts of a carb can be vey bad as it can enlarge the diameters of the many orifices of the carb and really screw everything up what do you guys think?

Just following the detailed instructions in the carb cleanup series which is now available formatted for downloading and you will be successful. Don't fear, help is only a post away.

[Anonymous]

Thanks!

Well I just got the old beast running! On gasoline no less. after doing some research in the preious posts i read that sometimes leaving the air cleaner off is enough to screw up the mixture so much that the bike wont run. I'm sure that going throught the carbs another time didnt hurt either but everything was really clean already. Anyhow thank a lot guys for all your help. the bike runs great now, I just need to do a little more tuning on the idle and she'll be perfect! Thaks again
Rider Rob