GS750: long warm-up interval. Also, bogging

[Longitudinal]

With the throttle open the choke is NOT doing it's job, it only enriches with the throttle nearly closed, when the pilot circuit is working. At wide open throttle it does nothing. If it runs better wide open when fully warmed up than when cold it is too lean.

So we agree. Very good.

[Speedo]

Longitude dude - I moved out here FROM columbus oh 5 yrs ago and I lived there for almost 20yrs so i know first hand there are some really good cycle dudes & shops near you. Have you tried "Rice Paddy"? If still in biz, those guys were awesome.

Anyway, here's my 2 cents:
1. Listen to all these guys. They are really, really (really) good.

2. If you went to airfilt pods from stock, you ABSOLUTELY will need to rejet. I crashed my first 78 gs750 back in '85 (described below is my 2nd) when i went to pods before i had a chance to get rejetted because it ran so wierd. It had a header, but that makes not difference. Do it. If there is a "real" improvement in "breathing" (i.e. exhaust like header, or intake like pods), you must rejet. More air needs more fuel. If you wouldn't have to rejet, then there would be NO improvement in breathing. Think about it.

Carb jetting is both a science and an art. Ideally, you (or whom u hire) know what you are doing, have patience (lots of it), and a dynamometer to empircally measure results of changes. I went with such a guy in Columbus back in 90's. It was perfect. All throttle positions. Totally worth whatever $$ I paid the dude. Unf, I know he closed his biz (took a job as a crew chief on some bike race team). I know this because when I went to the smoothbores (source: Rice Paddy), I knew i needed to rejet again, and I could not find someone as good. The bike still doesn't run as good as it did before. Perhaps I'll find such a shop/guy out here but meanwhile i'm dealing with some other problems...

3. Are you still running points? Am I reading that right? If so, I assume stock coils too? Both weak points and both make these bikes "cold hearted beoches" as far as warming up. Again, 30 yrs, 2 gs750s of experience speaking here. About the only other weak point on GS's is the charging system (see my other posts) and the clutch if u hotrod it.

Go Dyna S ignition and dyna coils. It will fire up and warm up like never before.

4. O rings / intake boots. If you can find them, by all means change. Once of my boots had a pinhole in it years ago. All O rings were brittle. The difference is like night an day. btw, when cleaning bike, hit the boots and any other rubber stuff (ex tires, NOT) with 303 protectant. Will last almost forever.

5. Last, as RustyBronco and Chef1366 and others suggest, before you jet/rejet, MAKE SURE (for real) that you have good spark and there are NO vacuum leaks and NO fuel leaks dripping fuel is usually float sticking btw) or you are just wasting your time solving the wrong problem at the wrong time.