78 gs750en carb cough or spit.

[thekegk]

as stated i have a 78 gs750en with v&H megaphone exhaust and K&N pod air filters.

i have rejeted to a main jet of 130 since i don't have a adjustable needle. does this sound about right? and the issue is i have a small spit i guess randomly from random cylinders when i have full choke. it some times gets to the point of making the bike drop for 2000rpm to around 1000 when this spit happens, i have used a carb sync on my engine and got them as close as i could and i have dipped my bowls and jets in carb cleaner but i didn't take the whole carbs apart. also while riding when i let off the gas i get a backfire as the bike idles down but if i pull the clutch in it stops. is that from the short megaphone exhaust or carbs?

onto a side note i have a charging issue since i think my stator or rectifier is bad.

well any ideas would be appreciated.

thanks keg

[mark]

Are you sure you're needles aren't adjustable? What kind of carbs do you have on your bike? I'm not real familiar with your bike, but it should have VM carbs right? They do have adjustable needles.

With stock carbs, just replacing the main jet won't cut it with a pods, megaphone set up. I put a 4-1 pipe on mine and kept the airbox stock and a needle adjustment was required to get the thing to run right.

[thekegk]

no its not the vm carbs ill look and post what they are cant remember of top of my head

[chef1366]

You should have VM carbs unless the head was changed.

[thekegk]

i guess it does now that i look at the parts fitch i didnt know it was inside the slide in the carbs, well seeing as i now know that whats everyones recomendations for my carbs jet size and possible needle position?

[KEITH KRAUSE]

The only chance the stock jet needles have of working is to put the needle e-clips in the bottom (5th) position. Test at 1/3 throttle position.
I suggest a Dynojet ket kit but you can try the above adjustment if you like.
Don't forget to re-bench synch the slides after making any needle adjustments. Then vacuum synch. Taking plug reads/testing will not be accurate without a vacuum synch.