K75 Mileage- What do you get?

[stagewex]

So I'm down in Daytona for Bike (or rather Trailer) Week. Trailered my '95 K75 and my friends 2013 r1200rt down from NY. We are having a ball. It's also the first real time I've had to really ride the bike a lot and put here through her paces. She is as tuned-up as possible and I changed the fuel filter, put some new Metzlers on her and did a full spline lube before leaving. From the time I left NY last Friday (it snowed) till today (83 degrees) I have put close to 600 mies on her and she is running sweet. But the milage is confusing to me and I was wondering when in fact others start seeing the low fuel light come on and how many miles to the gallon you all get.

Check out my last 3 days of fuel-ups and let me know what you think. Also keep in mind that I am in Florida and 70MPH is slow on these highways so all highway riding is at 70 to 80+. And it's all highway riding.

March 7th:
Reserve Light came on at 118 miles.
The bike took 3.68 gallons at 138 miles ****I was running 93 octane and switched to 89 octane at this fill-up****

March 8th:
Reserve Light came on at 129 miles.
The bike took 3.68 gallons at 150 miles

March 9th:
Reserve Light came on at 123 miles.
The bike took 3.92 gallons at 157 miles

 

[pglaves]

The bike has a tank that usually takes 5.2 gallons from "out of fuel" to fill. With an intended 1 gallon reserve most of our several K75s have had the light come on needing 4.2 gallons. Your light is coming on a little early gallon wise.

BUT, you ought to be getting 40 mpg - not what you are getting so something is not as "tuned" as it ought to be.

I expect the low fuel light to come on at about 160 to 165 and to then immediately take 4.2 gallons. The float can be adjusted by bending the float arm to get to that 1 gallon reserve. It may take a couple of tries.

But you need to address why the mileage is as low as it is - even accounting for sea level, 70 mph, and winteer gas.

 

[Paul_F]

My K100RT gas mileage varies between good and awful depending upon how aggressive my wrist is with the throttle leaving a stop.

 

[mlytle]

my reserve light comes on with 1.25 gallons left. dry to full is 4.9 gallons. ( just measured these amounts yesterday after removing and emptying the tank for engine maint.)

get 40-45mpg.

 

[075038]

K bike low mileage: You've been getting right around 40mpg according to your numbers, not terrible. Which K75 fairing/windscreen size? My K75S only gets over 40 when my wife is aboard and we ride 35 -50 mph calmly. Solo and with 80 mph speeds, 40 mpg is fine.

Now gas has 10% alcohol. Did you ever hear of converting a gas engine to run entirely on alcohol for hot rod purposes? The motor needed bigger jets in the old carb days to get the same power and even bigger ones to get more power. That's because gasoline is more densely packed power than alcohol, so when the gas pump includes 10% alcohol we all don't go as far on a gallon. When 15% comes, mileage will go down further. I bet the car window sticker mpg test is still on 100% gasoline.

When getting 30 or so MPG instead of 39, I first changed the fuel filter then a great K bike tech found that my low mileage was partly due to sky high fuel pressure, he changed the pressure regulator on the fuel system and then I had a couple tight exhaust valves adjusted looser (to spec then) and my mileage came back up. It was a K100 2 valve just after a coast to coast round trip (USA).

 

[72bavaria]

My 92 K75s, best range I got out of a full tank was 230 mi. Easy to get 205 mi to 210 mi on tank. Example: Primm Nevada, to Cedar City, Utah 212 mi. Must fill the tank carefully to max.

 

[pglaves]

my reserve light comes on with 1.25 gallons left. dry to full is 4.9 gallons. ( just measured these amounts yesterday after removing and emptying the tank for engine maint.)

get 40-45mpg.

My dry to full is 5.2 gallons (compared to this 4.9) but I have removed the flapper valve and funnels at the fuel tank caps. I have also carefully bent and tweaked the arm on the floats to have 1 usable gallon left when the light comes on.

 

[CarlNH]

My '93 K75RT gets 48-50 MPG consistently in varied riding. Light comes on between 150 and 165 miles.

 

[tinytrains]

Commuting back and forth work on the LA freeways, 43 MPG. Exactly the same on my R1200R. When it was new back in 89, and I could not go over 55MPH due to break in, I got 55 MPG once!

 

[stagewex]

I got back yesterday. Spent a couple hours cleaning the bike. Even from being in Florida just 8 days, parking outside I could just see the beginning of topical rust over most of the hardware. Very salty condensation environment.

I filled-up and went for a more normal local ride. At 84 miles on the odometer I filled-up with 2.2 gallons. That sounds about right to me and what Paul was suggesting.
So I guess for this one week of experience the more aggressive you are on the throttle, it will take its toll mileage-wise.
I'll try to open and adjust the fuel sensor to come on at 1 or 1.5 gallons. I must have thrown it off/bent it when I installed the new fuel filter.

Someone mentioned fuel tank maintenance, what do you do?