78 gs 750, with all the problems

[therealdunbar]

hey, had a couple of posts going i figured i would consolidate, i will post the links at the bottom. Ive got a 1978 gs 750 E everything stock except the bars and the exhaust.
I have put on a k&n air filter and oil filter, new spark plugs, oem petcock with a clear vacuum tube,and drag bars. I've checked the compression, ignition points, pulled the plugs out and made sure they were sparking at idle and slightly above, cleaned the carbs (sprayed all passages with carb cleaner), synced the carbs, adjusted the float height to spec. the jets that are in there now are 102 main and 15 pilot.
The problems that i am running into; poor mpg(20-25) measured this many times using the same fill line, intermittent power when i roll on the throttle i believe this to be misfiring and plan on getting new ignition coils, fuel in the vacuum line aswell as the right side exhaust (from header # 3), headers 1-2 being hotter then 3-4
The thoughts that i've had were; float jet stuck open, o ring not seating properly, poor ignition coils. theres a hole in the exhaust on the left side im not sure if it would effect the performance much but i figured id mention it anyways. Im pretty sure i've covered everything, thank you to anyone who has already posted on my other threads any additional insight would be appreciated

http://www.thegsresources.com/_forum/showthread.php?t=196421

http://www.thegsresources.com/_forum/showthread.php?t=195797

[allojohn]

If I were you I would do a proper (completely apart and 24 hours in Berrymans) dip on the carbs (see BassCliff) buy a set of o-rings from Mr Barr and remove the carbs from the issue. BTW your float heights should be 24mm, see VM carb rebuild on BassCliff's site.

Sooner or later you will have to do this, might as well do it now and move on.

[btbarb]

Did you say you replaced the petcock with a new OEM petcock and you have fuel in the vacuum line?

[therealdunbar]

your right i will have to dip the carbs, ill look into this for the immediate future. i did replace my petcock with a new oem one and i am now getting fuel in the vacuum line i couldn't tell if i was before as the line wasn't clear but i knew for sure i was getting gas into the crankcase

[OldVet66]

Start with a valve adjustment, rebuild the carbs properly, carb cleaner is a waste of time until they have been thoroughly soaked, replace the O-rings http://www.cycleorings.com/ gaskets at Z1 Enterprises, check float height, insure the petcock is not leaking (not likely if it is new OEM and not in the prime position), replace the carb boots (OEM) and boot O-rings and keep away from anything that requires re-jetting until you have it running right. Then you can check out the electrical system. In the process you will be well on the way to being your own mechanic.

[Big T]

Unlikely that your coils are bad

Replace your points and condensors 1st

[MisterCinders]

your right i will have to dip the carbs, ill look into this for the immediate future. i did replace my petcock with a new oem one and i am now getting fuel in the vacuum line i couldn't tell if i was before as the line wasn't clear but i knew for sure i was getting gas into the crankcase

There should be no fuel in the vacuum line.

Return that petcock. It is failing. Change your oil and filter since you probably have gas in the crankcase.