1978 GS750E hesitates just off idle

[Himble]

I think this issue has already been discussed but I can't find a definitive answer.
My 750E, once warmed up runs fine to redline, but when I stop at lights or stop sign (idle is normal at ~1100rpm) and then open the throttle to take off, there is a slght hesitation before it picks up. This also happens when I change down to 1st (or 2nd) when going round a corner before opening the throttle again.
The bike is stock, however where the breather pipe connects into the airbox, there's just a hole. Not a big one, just a bit larger than than the pipe/hose. In an earlier life, it seems the entry point was broken off.

I'm not going to play with anything until I get advice/suggestions from all you experienced gurus on this forum! If you need more info to help, let me know and I'll try my best!

Cheers
Andy

[1978GS750E]

Try covering the hole with tape and see if it makes a difference. These bikes are very finicky where air is involved. The amount and flow of air is VERY important. You may be getting too much air!

[allojohn]

Could be low float height and or mixture related, since it's runs well elsewhere on the throttle band I'd start there. As for the breather, get a filter on the end and plug up the hole to the airbox.

[renorealtors]

I agree it sounds like a fuel problem possibly lean condition due to the hole or dirty pilot jet causing it to be lean at low rpm? Here is my ridiculous notes from my 1978 build I sold last year. Doubt it will help but you never know.

[allojohn]

Nice work there John, clean machine...

[rphillips]

A few yrs. back, my buddy & I went to look at a "99" Bandit 1200, he was interested in buying, it was doing just what you're describing + while just riding at 40 or 50 mph & crank the throttle, it would sputter once then run fine. My Buddy declined to buy it. The following week I contacted the seller & we worked a deal & I bought it. Removed the carbs, & found a little point poking up in the throat of one of the carbs. I think it's called the idle adj. screw had been screwed in tight enough the point had broken off. Got the little point out, installed a new one, got it adjusted right & all is great no stumbles, coughs, no nothing at any throttle position. Now mine were CV carbs & yours are VM's, may be different, but maybe may help. Dang that's a clean looking bike you've got there. congrats.