Fuel Range

[2000rsv]

'86 K75C.  Ride it fairly conservatively.  Filled with 87 octane, non-ethanol fuel (pure dino, baby  :2thumbup:).

The low fuel light came on at 130 miles.  Ran out of gas at 163 miles.  This range seems a bit short.  Put 5.1 gallons into the tank.

Is this normal?  (I know it's not, but what might be going on?).

BTW, I was running it out of gas as an experiment to see how far a tank would take me.  I had a full gallon gas can strapped on the Reynolds rack.

[johnny]

greetings 2000rsv...

if it were me i would be thinking about new air filter... new spark plugs... 2 bottles of techron in 4 tanks of gas... throttle body sync... and of course revving it on the redline more often than not...

j o

[Chaos]

what he said.  You should be getting 42, not 32 mpg, I get 48 at a steady 70mph.  Check the valve clearances too. 

[Grim]

Do you do a lot of short trips of under 5 miles?  Do you have the factory rated thermostat?

When a fuel injected engine does not reach full operating temp it runs a rich fuel map through warm up. So short trips or a lower then specified thermostat will cause it to use extra fuel.

My 95 k1100 gets 45mpg in the mountains on long runs but my short commute and local I get 37.

In the air flow meter on bikes so equipped is a ambiant air temp sensor. They some times collect dust and that insulates it causing issues with air temp. K&N filters make it worse as the oil creates a film.

Clean that sensor. It's a little knub on the inlet side of the AFM. It's in the side of the air box on Motronic bikes.

[2000rsv]

greetings 2000rsv...

if it were me i would be thinking about new air filter... new spark plugs... 2 bottles of techron in 4 tanks of gas... throttle body sync... and of course revving it on the redline more often than not...

j o

Johnny,

It has new plugs, throttle body sync, and valve clearance checked.  I did not replace (or check) the air filter.  Will do that asap.

Ran a can of Seafoam through it in the first tank of the year.

Will let you know about the air filter.

J

[Tomnel141]

It may not be a good idea to run a K bike out of gas. The fuel pump cools by sinking heat into the gasoline. When the gas runs too low to immerse the pump it gets hot. Big Brother sez this is doubleplusungood for the fuel pump. Also, fuel pumps are very expensive.

The idea of cooling the pump in gasoline is not as barbaric (or dangerous) as it may sound. You will either park the bike or buy fresh, cool gasoline in a fairly short time so it won't overheat the gas. This is the way most, modern fuel injected cars work.

[2000rsv]

Replaced the air filter and ran about 1000 miles through the UP (Upper Peninsula Michigan) earlier this week.  Averaged about 42-45 MPG.  Think we are OK.