are 25 year old floats most likely bad?

[BubbaZanetti]

especially if they've been sitting around in old gas a lot of the time?

i'm not very impressed with my mpg on the R80ST, it averages 40 or so at a steady 5K while highway driving, considerably less around town. i just bought new floats anyway as i was ordering a few things from Max, the old ones were pretty discolored.


also, does anyone know the REAL size of my tank? i saw a spec sheet that said 5 gal but i KNOW this isn't right because, well, the tank is too small and i flip to reserve at 120 miles or so (3 gal).

[lbrackr756]

When floats go bad it causes the carbs to piss on your feet. I've never seen where they just cause lower mileage. Today's fuels with alcohol in them do eventually make the floats go bad but if they're not causing a leak then they're probably still ok.

[jforgo]

Yes, they are almost certainly bad. I would replace out of hand - but i would also replace the float needles, for sure.

Spec sheet show 19 liters capacity.

The reserve may not tell you much about the fuel capacity, though. I have replaced petcocks on a couple r100's, and reserve is much larger now. i could cut short the main tubes if I wanted to.

[barryg]

I bought a R80ST years ago. I've been accumulating parts for an upgrade. I knew that tank was to small on capacity. So I acquired a stock R100GS tank, I think it holds at least 1 more gallon than the ST tank. I think a R100R is the same tank as the 100GS. Probably the easiest way to increase fuel capacity. Some adaptation required, to add to ST. I've seen a lot of pictures of ST's with these tanks.

[BubbaZanetti]

Yes, they are almost certainly bad. I would replace out of hand - but i would also replace the float needles, for sure.


my thought, the bike only has 19000 miles on it, i rebuilt the carbs (minus the floats) and all the needles looked good, including the float needle.

[108625]

i'm not very impressed with my mpg on the R80ST, it averages 40 or so at a steady 5K while highway driving, considerably less around town.

Those aren't bad numbers for the bike at all. You'll probably notice an improvement in how the bike runs after a carb clean and rebuild, but nothing significant in mileage.
My R100 with it's lazy engine, 40mm carbs, and taller gears used to get better mileage than my wife's R65LS. I think your ST is geared next lowest to the LS, or close to it.
Keep in mind that old airheads' reputations exceed their reality, just like old VW Beetles. Those fish just keep getting bigger every time the stories are told.

[mymindsok]

Yes the floats are bad.

I gurantee it.

[keelerb]

AFAIK, my 84 R100RT has the original floats in it. Runs like a top (I keep it well tuned and maintained) and gets 40-ish MPG, despite ample, um, provocation).

So I don't think you can NECESSARILY judge solely by age.

I replaced my carb diaphragms on that basis, and the ones I took out looked perfect. Sorry I did it? No, but necessary? Also no.

FWIW/YMMV

[Colt03]

I would try running some Techron thru it, then change the oil and filter. I have run it in my vehicles and had good results.

good to see you this weekend.

Craig