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'86 K75C tank range?

J

jjennings

Guest
Howdy. My '86 K75C goes about 100 miles before the low gas warning light comes on. I get about 40 mpg so this means each time I put about 2.5 gallons. The manual states that the tank holds 5.6 gal. Additionally according to the owners manual the light comes on with 1.3 gals left in the tank. Although this isn't a drastic difference it is about .8 of a gallon. I have never run the tank dry (which is probably what I need to do some time) but I was wondering if any of you all have either experience with the same bike or can offer me technical assistance to what might be causing this slight incongruity. Misplaced fuel pump? Thanks.
 
Somethings not right.

If when you open the gas cap your bike still has the little cup and flapper removing it will allow you to put more fuel in.
It's easy, take the cap off by removing the screws that hold it to the tank, turn the cap over and remove the screws holding the cup in place, remove cup, replace screws, replace cap. Seems like you have to make sure the vent/overflow tube is attached.
I did mine 23 years ago so I may have forgotten something.
I typically go 160+ miles before the light comes on (depending on riding conditions). I wouldn't attempt to run it dry. If you do carry gas with you do it in the bag oposite the muffler (just had to say it). Removing the cup will let you see the fuel level easily.
The most fuel I've added while riding was 4.8 gallons and that was with 210 miles showing on the trip meter. How accurate is your odometer?
 
There is a float and lever inside the tank which controls the low fuel light, you need to adjust the rod so the light comes on later than it is now.
You should be abe to get a couple hundred miles out of a tank of fuel.
40 mpg is a bit low for a K75.
Gilly
 
I'm not positive the 5.6 gallons is right - but it might be. But the usable fuel is right at 5.2 gallons, maybe as much as 5.3 until you're pushing. Most bikes have the float set so it turns the light on about at 4.2 gallons used - leaving one usable gallon. If mine isn't set that way I adjust (bend) the float arm until it is.

Also - be sure the float isn't obstructed or pulled down by the hose in the tank.
 
Thanks all. I removed the inside flapper and took a look at the float. Then fill-up and we shall see. After reading posts I felt a bit foolish for not considering that the problem could of course be not filling up the tank completely. I certainly attempt to but perhaps the little flapper thing is keeping me from totally topping off. 5.6 is what the owner's guide says so I assume it to be true. Changed the plugs too and will see if mpg goes up. Does anyone know the standard range for '86 K75? Cheers.
 
Thanks all. I removed the inside flapper and took a look at the float. Then fill-up and we shall see. After reading posts I felt a bit foolish for not considering that the problem could of course be not filling up the tank completely. I certainly attempt to but perhaps the little flapper thing is keeping me from totally topping off. 5.6 is what the owner's guide says so I assume it to be true. Changed the plugs too and will see if mpg goes up. Does anyone know the standard range for '86 K75? Cheers.

My light usually came on at about 170 miles and I was pushing at 215
 
My guess is that you're sticking the fuel nozzle all the way into the tank just as you would a car. And when it clicks you're done, right?

I say this because this is EXACTLY what I did when I first got my K-bike. You need to use the end of the nozzle in just far enough to open the flap and fill it til the level hit the top.
 
Flap be Gone!

If you remove the flap and its cup; the tank is much easier to fill. You are pouring gas into a 2" hole. Getting the tank full is a snap. Riding the "blue hiways" I get about 50 mpg at 60 mph. Going 200 mi before the light comes on is assumed.

I have the non-US model without the cup or cannister.

Yes I know I am a foagy.:bolt
 
I guess I need to slow down...I can't resist the 80 mph and north range. My bike seems really comfortable there....I know the BMW speedo is a bit "optomistic" but out in the sticks of NV (or on I-5 between Sacto & LA) you need that 100 mph for that run from Ely to Tonopah....but you WILL run out of gas 10 miles from Tonopah. Can I REALLY get 50 mpg at 60 mph?
 
I have 2 kbikes, the fuel lights are useless. My K100rs, I usually get 150 miles before needing to fill the tank, my K75 goes about 200 miles. My fuel gauge is the trip odometer, Reset it every fill up.
I did however get almost 200 miles a tank on the way to the rally in TN. The reason for that is I let a friend ride my k75 to the rally. He is ridding on a learners permit, so we drove mostly the posted speed limits (55 -70), never over 80.

My bike (the k100) likes it up in the triple digits, but it uses some extra fuel :doh

Oh and both bikes have the 2 fuel lights, (85 and 86 models) the yellow one doesn't work at all, the red one sometimes on the k100 and unusually on the k75. The odometer always works; well not always....... if you own one ....you know what I am talking about.

Chuck
 
I know the BMW speedo is a bit "optomistic"

I tested both my speedos with one of those trailer mounted radars, you know the ones the police put out so people relize how fast they are going.

They left it there for a week ;) I went past it at 30, 40, 50, 60, 70, 80, 90, and 99 :bolt. it was only 2 digits :sick Mine are right on, or the radar is off.
 
I tested both my speedos with one of those trailer mounted radars, you know the ones the police put out so people relize how fast they are going.

Either my speedometer is inconsistent or those trailers are. I get different readings on different trailers.
 
Isn't the goal to make the lights say 99?

Yup, then you get a free game!

My light always comes on at about 150 miles and then it takes ~3.5 gallons to fill up. I was also not filling her up correctly when I first got her, and the light was coming on around 70-100 miles. You need to just stick the nozzle in enough to open the flapper. And top off 2 or 3 times.
 
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