Petrol Tap

[Ed Miller]

My ride is almost all back roads.  There are stop signs and those farmland 90 degree turns complete with gravel on the pavement, but no traffic.

I took the ferry this morning so I could skip some new chip and seal application.  

[montmil]

Ok, all you guys with 200+ miles to a tank.. what am I doing wrong? I consistently get 35 mpg, have to fill up around 170 miles.

The bike runs well, my usage is half city streets and half parking lot / highway (i.e. rush hour).

Don't envy you in that Austin traffic mayhem. As such, 35 mpg sounds good.

A side bar note: Your poor battery is getting very little actual charging while you're doing The Mo-Pac Shuffle. Not much juice amping your battery until the engine gets about 3-4K revs and stays there awhile. Do you keep the scoot on a Battery Tender?

[tvrla]

You'll get the best mileage in the power band - something like 4-5K RPMs in fourth or fifth gear. That's the most efficient use of the fuel - the greatest distance traveled per power stroke.

As for why mine does so well - it's not stock and is really well set up. I never would have expected one machine to have so much power and still get great mileage. I didn't set it up, just put it back into shape, and I'll say that whoever set it up did a wonderful job of it (I suspect it was San Jose BMW - CC Products). Because it has so much power I upped the final drive from 3.56 to 3.36, and still have no problem passing just about anywhere I want. I suspect a 3.20 or 3.09 will do just fine - but why mess with it when it's already getting 50mpg? Anyway, the taller final drive has to have helped the consumption as well.

[Luca]

Anyway, the taller final drive has to have helped the consumption as well.

It helps if you have the extra power.  Not sure if stock BMW configuration would benefit so much from this.  Rider weight will also play a role... the bike is only 450 lbs.

The 6 cylinder Saturn Vue had 100 more horsepower than the over-worked 4 cylinder, but was within 2mpg city/highway.

[tvrla]

Larry Chabira in Austin TX claims the 3.20 works well on his R65. That's a couple steps higher than mine.

[montmil]

Larry Chabira in Austin TX claims the 3.20 works well on his R65. That's a couple steps higher than mine.

Larry's got another R65? I bought my second R65 from Lamont. He lives but a couple miles from both son's homes in Austin. Cool cat, Larry is. I need to chase him down next visit to Capitol City.

[Matt Chapter]

Don't envy you in that Austin traffic mayhem. As such, 35 mpg sounds good.

My rule of thumb is: leave the office by 4 at the latest.

I have one of those fancy sealed AGM batteries now, so it hasn't needed the charger yet.  I hook it up and the light goes green almost immediately.

I suppose a good comparison would be to take a road trip without traffic, but I still feel like I should be doing better than 35 mpg.  I almost never actually end up standing still in traffic.

[tvrla]

Larry's got another R65? I bought my second R65 from Lamont. He lives but a couple miles from both son's homes in Austin. Cool cat, Larry is. I need to chase him down next visit to Capitol City.

He says he's got a 3.20 on his R65 and it handles it just fine. That's all I know. From that statement it sure sounds like he's got an R65.

[tvrla]

I suppose a good comparison would be to take a road trip without traffic, but I still feel like I should be doing better than 35 mpg.  I almost never actually end up standing still in traffic.

A few things can cause high consumption - worn needles and needle jets, leaking enrichener gaskets, heavy floats or incorrectly set floats that allow the fuel level to go high.

I'd imagine if you're a big guy and do a lot of city riding, it could amount to 35 mpg.

[Fraggle]

thanks for the replies - been on hols for a week or so and the mrs doesn't let me near a computer when I'm supposed to be giving her my undivided attention.

So bike is new to me, have done around 500 miles on it. Single petrol tap.

I had it "on", and thought I'd run it till it went on reserve but it just ran out. Tried the old lean to the left tric, but the tank was nearly dry.

I suspect that at some point someone has mullared the tap to give it maximum range. The manual I have is ambiguous about the tap (in fact just about everything is in that silly book - whatever vehicle I buy, I manage to get the one that is with in the haynes crossover years - pre 1980 models do this, 81 on do that and mine is an 80 that seems to do neither...

Looks like a tap strip when I can be bothered...

[montmil]

Easy enough. Detach fuel line and remove the petcock assembly. Look for the petcock's "straws".

Removing the reserve function on the petcock won't add range... unless you count how far you'll have to be walking when that sucker goes dry on you.  

[Matt Chapter]

leaking enrichener gaskets, ...

I'd imagine if you're a big guy and do a lot of city riding, it could amount to 35 mpg.
 

5'7, 155 soaking wet, so.. probably not?

But my choke is worthless, so I'm suspicious.  I'll have to consider that next time I'm in a tinkering mood.

[Fraggle]

maximum range in the sense that you don't have a couple of litres of fuel sloshing around on the "wrong" side of the tank.

I don't have special needs - I realise that a petrol tap without reserve won't affect range;)

[Luca]

While there are a few ways to test your setup, a simple inspection is probably the easiest.  Just be ready for the tank to spill a fair amount of gas after you "empty" it.  If you put the tank on its side on a lawn or piece of carpet you can keep that extra gasoline from spilling everywhere (but if you do spill it on the lawn the grass is dead for a long time)

But back to hypotheticals... if they took out the main straw but left the reserve straw, you could run the bike on reserve and have a small amount of fuel left when you turn it to main.  Not as much as a stock configuration, but hey, it is possible.