Help! Carb woes! 1978 GS750EC

[Anonymous]

I'm rebuilding my bike, fresh paint and everything, so while it was all apart, I decided to clean the carbs because it ran like crap when disassembled, and, while in there, I should just take care of it. My problems began immediately, when I noticed my carbs don't exactly match the diagrams from bike bandit. It looks exactly the same, except that on the bottom, engine side, there is another adjustment screw. Looks just like the pilot air screw on some other bikes, but I also have a pilot air screw on the side of the carbs. Normally, this wouldn't be a problem, as I counted the number of turns out from seated, 1.5 turns, so I could just set them back where they were. Unfortunately, becuase they are brass, two of the heads are pretty stripped, and cannot reinstall. THEY ARE ACTUALLY BRITTLE, the heads are breaking! Now, because I cannot locate them on bike bandit, I don't know where I can get them. They are sharp pointed tapered adjustment screws that appear to affect the pilot jet (carb cleaner injected into the adjustment hole pours out the pilot jet). Can anyone tell me what this Is? I could also use some info on basic setting. I can rebuild engines all day, but I HATE carb work... I know there are like a billion threads already on this topic, I just didn't find any about this darn screw

[earlfor]

Re: Help! Carb woes! 1978 GS750EC

The screws protruding through the float bowls underneath are the pilot fuel screws. Turning them out increase fuel flow. Mine were set to 1 1/4 turn out on my 79 750. The pilot airscrews are on the sides of the carbs. Mine were set to 2 turns out. Set the float heights to 24 mm.

Fuel pilot needles come in the carb rebuild kits from cyclereycle. I suspect you could find them listed on the carb diagram on bike bandit though and order them for a few dollars. the rebuild kits are about $25 per carb.

Earl

I'm rebuilding my bike, fresh paint and everything, so while it was all apart, I decided to clean the carbs because it ran like crap when disassembled, and, while in there, I should just take care of it. My problems began immediately, when I noticed my carbs don't exactly match the diagrams from bike bandit. It looks exactly the same, except that on the bottom, engine side, there is another adjustment screw. Looks just like the pilot air screw on some other bikes, but I also have a pilot air screw on the side of the carbs. Normally, this wouldn't be a problem, as I counted the number of turns out from seated, 1.5 turns, so I could just set them back where they were. Unfortunately, becuase they are brass, two of the heads are pretty stripped, and cannot reinstall. THEY ARE ACTUALLY BRITTLE, the heads are breaking! Now, because I cannot locate them on bike bandit, I don't know where I can get them. They are sharp pointed tapered adjustment screws that appear to affect the pilot jet (carb cleaner injected into the adjustment hole pours out the pilot jet). Can anyone tell me what this Is? I could also use some info on basic setting. I can rebuild engines all day, but I HATE carb work... I know there are like a billion threads already on this topic, I just didn't find any about this darn screw

[Anonymous]

Okay, today I hauled the bike to my new home, 4.5 hrs south of where it was. THere are two problems, an electrical gremlin ( I can deal with that on my own, I'm a professional gremlin hunter) and the carbs run like crap. What order should I tune in? I figure I'll arbitrarily set the pilot fuel screws ( thank you earl for recommending the keyster kits, they are perfect) at 1.25 turns out, then warm bike up and adjust the pilot air screw for maximum idle, set idle, then sync? Sound about right? Where should I set the new adjustible needle to start, I for some reason remember it should be set on the 3rd notch. This bike if back from a fresh paint job and pictures are soon to follow!

[KEITH KRAUSE]

If you're using the stock air box with the lid still attached, your jet needle e-clip should go in the 3rd position, or notch. Be sure you put the plastic needle spacers back in the same order too.
If you have a manual, verify this. Your carb spec's will show the jet needle # followed by a "-3" or ? The number following the dash is the e-clip position.
Whenever the needles are disturbed on VM carbs, you must bench synch and then vacuum synch the carbs to avoid mixture problems.