Reserve switch

[magge52]

Wanted to test out how the reserve works since it's all new to me. The manual says to hit the reserve switch when the gauge gets to E. I let mine get below E without switching to reserve to see how long the engine would run-but it never quit. She took 5 gals even when I filled up so I'm assuming it was running in the reserve range. Did it go to reserve by itself?

[Pat Conlon]

That's the safe way of doing it...switch to reserve before the engine stumbles.

I have left my reserve off until my engine stumbled...only to have it happen in a passing situation.

Not recommended.

[magge52]

That's the safe way of doing it...switch to reserve before the engine stumbles.

I have left my reserve off until my engine stumbled...only to have it happen in a passing situation.

Not recommended.

Sounds good, I thought it would have hit reserve before then. I got about 38mpg on that tankful. Seems a little low from what I've read on the board.

[Pat Conlon]

Depends....42 seems to be the norm...except for a certain simian here on the forum...he reported as high as 50 mpg, but he rides downhill with his engine off....

When was the last time your valves were adjusted, carbs synced, fresh plugs and carbs cleaned?

Do you have any jetting changes? Airbox/Exhaust mods? What are your sprocket sizes?

Riding habits are a major factor.

[andyb]

Seems a ballsy way to test the reserve.  I'd have to carry a bottle of fuel with me.  My luck, I'd have one setting, and would learn that in an unfortunate place.

[Pat Conlon]

I had a friend riding with me...but yea, you're right....dumb, dumb, dumb.

[rktmanfj]

I pushed mine about 3/4 mile one day last week (don't ask).  I highly recommend avoiding that if you can

[Mauro62]

42MPG??

My goal is to do 35 riding like an old man with an hat on his head. Normal fuel consumption for me is 33 mpg and I also have a 18 teeth sprocket instead of 17 OE on my 91 3xv.

I believe your gasoline is better than the one sold in Italy   

I did 47 with my previous byke "BMW GS 1200 MY 05" but I believe that less power, fuel injection and two only cilinder are enough to have less consumption.

[andyb]

Same sized gallon?  US vs UK is different.

Miles are the same whereever, at least.

Check for ovalled emulsion tubes (or needle jets, two names for the same thing) as well as for needles with unusual tapers due to wear.  Your plugs will tell you you're very rich in the midrange, if you ask them and this is the problem.

I usually do rather worse than 35mpg, but my vision of an old man with a hat on his head is a lunatic wearing a helmet, so...

[Mauro62]

Same sized gallon?  US vs UK is different.

I buy liters and ride kilometers   , I tried a conversion of my average 14km/l, may be is not correct?

In Italy we figure old men with hats being very slow drivers and creating traffic jams

[keand3]

Same sized gallon?  US vs UK is different.

I buy liters and ride kilometers   , I tried a conversion of my average 14km/l, may be is not correct?

In Italy we figure old men with hats being very slow drivers and creating traffic jams

I Just measured my consumption today and got 0, 5 liter pr 10 km or 47 mpg if you like. This was with extreme driving on fuel economy... no fun actually.

Your 14km/l would sum up to be approx. 33 us mpg i think:-)

[FJmonkey]

Depends....42 seems to be the norm...except for a certain simian here on the forum...he reported as high as 50 mpg, but he rides downhill with his engine off....

I have since left the OEM world (and 50 MPG) with slip-on Suppertaps, UNI pods and proper jetting. My fuel average since is 44.6 MPG.... I think I still kick Steve's ass on his stock bike... 

[magge52]

Depends....42 seems to be the norm...except for a certain simian here on the forum...he reported as high as 50 mpg, but he rides downhill with his engine off....

When was the last time your valves were adjusted, carbs synced, fresh plugs and carbs cleaned?

Do you have any jetting changes? Airbox/Exhaust mods? What are your sprocket sizes?

Riding habits are a major factor.

Well, I just bought the bike 2 weeks ago, haven't done any maintenance yet outside of a general cleaning and lubing the chain. It's all stock with 12k miles. This is the first tankful so I'll check it a few more times to get a better idea.

[Bill_Rockoff]

Wanted to test out how the reserve works since it's all new to me. The manual says to hit the reserve switch when the gauge gets to E. I let mine get below E without switching to reserve to see how long the engine would run-but it never quit. She took 5 gals even when I filled up so I'm assuming it was running in the reserve range. Did it go to reserve by itself?

In theory, the fuel pump cuts off with low fuel level when the switch is in the "normal" position, and will keep going regardless of fuel level(*) in the tank when you set it to "reserve."  (*)The pump will run for five seconds on a timer if there's no / very low pressure.)  If there is a problem with the switch or the tank level float mechanism, it might just continue running the pump in normal operation instead of cutting it off in the "reserve" function, which would basically be like "going to reserve by itself."

The FJ tank holds 5.8 gallons.  If you filled it using 5 gallons, you had 0.8 left.  And on mine, that's about where it starts to require "reserve" in order to keep running.  So, you probably haven't actually tested the functionality yet.

My fuel light usually starts to come on at about the 5 gallon mark, and it will start to run a bit rough shortly after that as the fuel level varies enough at the float to shut the pump off here and there.  Not long after the light comes on steadily, the pump will shut off, and the bike will quit fueling.  On the highway, it bogs and loses speed in gear until I switch to reserve, at which point the pump starts up again and fills the carb bowls enough to resume full power after a couple of seconds. 

It just now occurs to me, if it takes more than five seconds to fill four empty float bowls (a possibility I guess if they're REALLY empty) it will cut the pump back off before giving the carbs enough fuel to run the engine.  Maybe that's what happened 20 years ago when I ran mine dry at 202 miles on the tank; I switched to reserve, it didn't resume power, and I coasted to the shoulder and had to push the bike a mile to an exit ramp. (If I had left it on Atlanta's I-285 by Cascade Road, it would have been gone when I returned with fuel.)  Maybe if I had cycled the key to reset the timer for another 5 seconds, it would have fired right back up.  Huh....

I have been getting 38-40 mpg lately, needing reserve at 190-200 miles per tank.

[Bill_Rockoff]

Edited to add:  With a plastic fuel can bungee-netted onto the back of the bike, you can safely run it until it quits and then switch to "reserve," and if it turns out that the switch isn't operating correctly and you've used the whole thing, you have a spare fuel container with you.