'80 GS750 Brat build

Well,

I decided to try an experiment. I popped off the right side cover and slid a sandwich baggy over the UNI filter under the seat and used a rubber band to keep it there. It covered about half or slightly more of the filter and I wanted to see if this would fix the bogging on the low end.

It sure did. The bike came alive again. I stopped and filled her up then hit the throttle some more as I ran it through town. I stopped and took the bag off at one point and it didn't take long to see that it was a bit hesitant and boggy in the low end again. Stopped again...put the bag back on and it was back to its snappy self.

I suppose I have maybe 4 options the way I see it.
1. Do some mods to the stock air box and see if I can't fit it in around the seat tabs I welded in.
2. Come up with some sort of half cover for the air filter...or use the bag and rubber band
3. Go up a size or 2 on the pilot jet
4. Bring the floats down to 20.4 or even less to get back to what it was at before

I'm thinking about just restricting the air flow on the intake because I have no plans on opening up the exhaust which I feel like I would need to do if I up the pilots.

The fact that it still isn't running like it was before with the floats at 21.4mm says to me that they were probably down at 20mm which makes me really wish I had actually measured them before I changed them. I just know what the gap was definitely bigger than 1mm between what they were and the calipers I had set to 22.4mm when I checked them. I think they were easily 1mm lower than the lowest suggested float level and the stock airbox hadn't been taken off yet when they were set that way. It had to be running rich with the fuel level that high and the stock air box with the PO.

I hope I can find a balance in here somewhere. I'm curious what the fuel mileage will be on this next tank with the fuel level down where it should be and some restriction back on the intake side.

I rode 25miles yesterday with the baggie on the UNI filter and a stumble off idle became more noticeable as I went. When the float height was at 22.4mm the stumble was gone, but at 21.4mm it was back. When I got back I decided to take the air mix screws in a half a turn and see what happened. The idle was up and the stumble seemed gone. I only took it up and down my road to check, so the next ride will hopefully show if that was enough.

So I'm at 3 turns out, floats at 21.4mm, a UNI filter in place of the stock airbox half covered with a sandwich baggie...interesting setup here...

Hi, I've got an 81 GS750E. I swapped out the filter plenum/airbox for pods. Idle was fine but trying to apply any throttle past about 1/8 would just bog. I ended up getting a Dynojet Stage 3 kit and it's running great now. I am going to be changing the main jets again as the ones they supply with the kit are to big.
The biggest thing to change are the needles. The Dynojet ones are extremely different from the stock needles.

I also have a 4-1 exhaust.

The bike is working way better than it was when I got it.

I'm hoping to tear it down and rebuild it as a brat this winter but we'll see what happens.

The Gs750's one of the best engines ever made yet very sensitive to air and carb modification , please consider to rejet accordingly . jetting will vary from one region to another " i am speaking from solid experience with this particular model GS750 e with the mak vm29 carb" , do not follow generic jetting info out on the web , calculate your jet according to your area and may the odds be with you . here is my "yet to be completed build"