V11 gas mileage discussion

[docc]

ran my sport dry with 167 miles and filled it with 4.7 gallons

 

35 mpg

Yeah, the early tanks trap a lot of fuel on the right side.

[LowRyter]

ran my sport dry with 167 miles and filled it with 4.7 gallons

 

35 mpg

Yeah, the early tanks trap a lot of fuel on the right side.

funny, the tank isn't quite symmetrical. It does slightly bulge on the right.

 

what's the fuel capacity?

[gstallons]

What ever it takes to fill it. This is due to fuel tank bulge. And a smart-alec answer.

[docc]

Yet, truly, there have been different reports of fill volume from empty. Some could be from when we decide to stop pumping as the filler neck extends into the tank a bit. Upright or side stand affects fill volume. Certainly, a lot of variation if you simply insert the nozzle rely on the automatic shut-off.


The tank was billed as 5.8 US gallons, but I'm out of fuel at 5.1. The "tip-slosh" technique could get you a short piece further down the road (get off the sputtered-out Guzzi and tip it as deeply to the left as you are able and slosh some of the fuel out of the right side. The closed loop fuel injection will immediately begin pumping unused fuel back into the right side trap. My theory is use use as much throttle as possible in this circumstance to minimize the number of strenuous "tip-slosh" sessions on my way to redemption.

[Skeeve]

The thing is my old Guzzi’s got 45~50 MPG with carbs. My Breva which was stock except for a Mistral slip-on and it got 45~50 MPG. My 02 LeMans I got rid of because on a really good day of highway riding it got 34MPG. My current RM thus far has gotten a best of 34MPG. While it runs great under all conditions now the mileage on these V11’s is pretty pathetic. So what’s the fix?

 

The small valve Guzzis have better charge velocity & hence better combustion. Your Breva has Guzzi's dual-plug band-aid and redesigned piston, along w/ slightly smaller intake valve & decidely smaller intake ports to bring the charge velocity & mileage up, but it makes less total power than a V11.

 

Go read the threads on Mike Rich pistons, combustion chamber design & other stuff that's all about 2 site redesigns old now for the real low-down. Don't forget the less than stellar factory fuel mapping [not entirely their fault, smog regs lead to a bunch of nonsense for a/c motors] for V11s as well.

 

But to keep things in perspective, my old '79 Yamaha XS11 never got any better than about 30mpg, and that had a state of the art combustion chamber for back in its day, not the roughly 60 y.o. combustion chamber design on the V11...

 

Carbs work great on kick-start, magneto-ignition dirt bikes where you need stone ax reliability 'cause you don't want it breaking down 100mi out in the bush. On a street bike, the performance potential of EFI and computerized ignition & timing make up significantly for the potential of having to haul the bike to a shop if anything should go wrong.