Questions, Questions, Questions

[LiteFiter]

I have a "79" Special with 16,500 (I think) miles that I purchased at the end of this past season. Sat for 5 years in cold storage with fluids in it. I had the carbs thoroughly cleaned, changed all fluids, performed a tune-up, rebuilt brakes, and bike runs fine. Some questions about this bike since I have ridden nothing but Harley's since 1990 and have never owned an 1100. Closest I came was a new "78" 750 Special which I was relieved of in 1980 when it was stolen. I haven't ridden on a shaft drive since, so, I have a few questions:
A) My mileage is not as good as others seem to be getting according to this site. At best, if my odometer is to be believed, is approx. 27 city, and maybe 31 on the highway. Performance wise, bike feels great, idles smoothly, no back fires, no leaks of any kind, goes quickly with no hesitation when I need it. All the gears seem solid when shifting, no slippage, so, all in all, from a running stand point, its great. (BTW, no windshield either, I am a straight up rider) I just don't get the mileage issue. I'm not an aggresive rider, aside from the safety aspect, (I am 58, and so far, I don't think I am getting any younger), this bike really feels solid and I intend to keep it that way. But this has me puzzled. So what could be going on here?
B) Something the bike does seems odd, when I am in 1st, clutch pulled in, if I goose it a little, it feels like the back end rises a bit. It doesn't pull, but I can definitly feel it in my seat, and legs. Is this normal with a shaft? I doesn't concern me, until one of you tell me I need to be concerned, but I am curious as to what dynamic would cause this?
C) Any benefit to running Premuim non-ethanol? I get that running non-ethanol would be a bonus from gasket, varnish, etc. point of view, but is there any issue with running a higher octane? I have run a couple of tanks just to see if it had any effect at all on the mileage/performance, and didn't notice anything one way or the other.
Thanks ahead of time for whatever advice you can give me.

[Schming]

LiteFiter,

A. Have you had the carbs vacuum synced and to be thorough colortuned simultaneously ?

B. Your clutch adjustment may need to disengage a wee bit more.

C. Premium Non Ethanol ? If I could find any non eth. fuel that's what I'd be using. My bikes, and other power equip., don't get exercised enough so I add some fuel stabilizer upon fill ups to help with the degradation of the fuel.

Do you have the correct spark plugs ?
Have you performed separate ohm tests on the coils,high tension leads and plug caps as the engine may not be burning all of the fed fuel.

What type of exhaust is on the bike ?
I just pulled the, who knows how old, baffles out of my Jardine mufflers to find a substantial amount of rust scale and deteriorated packing that would inhibit flow.
IMHO all engines can benefit from a little help to breathe.

[DGXSER]

As to the millage, well, it does vary on your throttle work. Have you checked your timing advances are working? Both mechanical and vacuum? Synching and tuning the mixture will play a part, what color are the plugs?

I run nothing but 87 octane. The consensus on this site by those much smarter than me is that higher octane just cost more and adds nothing to performance, or mileage. My own fill ups and checking would support this theory.

Glad your enjoying the bike!!

[crazy steve]

The mileage issue could be what has already been mentioned, but you don't say if you still have the OEM airbox or pod filters. If pod filters, it's probably been rejetted and may be a bit rich. But definitely look at timing and your vacuum advance to make sure it's working. In order to get maximum mileage tuning has to be very good. I bought one of my '78s new, and typical mileage was in the mid-30s, I rarely hit 40 mpg.

The 'rising' is normal; that's the torque reaction from the motor. These turn opposite to most...

Stick with 87 octane. Higher octane can actually reduce mileage and also promotes carbon build-up.

[Yard Dogg]

The float adjustment on these bikes is probably the most finicky I've ever come across. This is my opinion and others may disagree. Seems like if I set the floats 1mm too low, it is hard to start when cold, and when I set them 1mm too high, it runs rich and gets bad mileage. When my XJ was running last, it was hard to start and got bad mileage, of course I didn't have 5th gear so that may have been a factor.