81 gs 750 tscc mid range rpm sag

[SixteenValve]

bike rain great at all RPM's before carbs were "rebuilt" by shop. i am not exactly sure what they did. i now have very noticeable sag (feels almost like starved for fuel) between 4K and 4.5K rpm. runs good in all other ranges. is this a screw i can adjust on each carb to fix it, if so which screw and how do i do it. thank you.

[tkent02]

Sag at which throttle setting?
It's either a wrong jet, needle position, or most likely the float level has been adjusted incorrectly.
A shop's job is to sell new bikes by messing up the old ones, don't ever go back to get your bike fixed.
It's all do it yourself stuff, no one else will do it right.

[OldVet66]

You have different carbs from my model, but while I was going through re-jetting, I had a mid range bog that was caused by the needles being too high and running too rich. I would run it up into the range where it "sags" cut the throttle and ignition and check the plug color. If it's too rich it will be dark and sooty. You are going to have to do what most all of us have had to do and learn how to rebuild your carbs yourself. It's the only way you will know what's going on in there. I know the idea is hateful, but there are few who have had an outside source rebuild their carbs satisfactorily. There are some on the forum that can do quite a good job if money is no object (meaning having rebuilt carbs rebuilt again).

[mrbill5491]

The 80-81 GS 750s really don't hit their power curve on the cam until about 4,000 rpm and if yours' is sagging/bogging, yeah I would say who ever did your carb rebuild goofed it. Time to yank the carbs off and do it yourself. There is a wealth of info on carb rebuilding on this website. You'll need to order some bowl gaskets, some carb plugs and most likely the intake boots as well if they haven't already been replaced. Get the o-ring set from Cycleorings.com. Check your fuel petcock and make sure its working right, these vacuum petcocks can be the sh*ts at time lol. Let the fun begin!

These 30+ year old bikes need a lot of TLC especially if they haven't had any in some time. I know, I'm doing alot of work on mine right now and it's amazing what age and heat does to some parts and my bike gets tons of TLC.