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Ummmmm question...........

822 views 16 replies 8 participants last post by  Tidefan1967 
#1 ·
Riding home from an appointment today, cruising 65, right before exiting 9a my low fuel light kicked on. I looked at the trip odometer and it read 69.2 miles :confused:
confused i filled up and it took 3.81 gallons. Ok little over a gallon left until push mode. An astonishing 15.4 miles per gallon.
Ok, thinking....big engine...lots of room to play with gear/speed selection.
Trying to use the ole butt-o-meter to determine best shift speeds was apparently waaaaaaaaay off!

Got home, broke out the trusty owners manual and checked recommended up/down shift speeds.
1 to 2 = 12mph
2to 3 = 19 mph
3 to 4 = 25 mph
4 to 5 = 31 mph

down shifting

5 to 4 = 22 mph
4 to 3 = 16 mph

drop to first below 9 mph


this whole shifting speed on this bike confuses me. Such a large bore engine one would think the shift speeds would be way higher to get the power out of it.

why such a low gear to speed ratio?:dontknow:
 
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#3 ·
Riding home from an appointment today, cruising 65, right before exiting 9a my low fuel light kicked on. I looked at the trip odometer and it read 69.2 miles :confused:
confused i filled up and it took 3.81 gallons. Ok little over a gallon left until push mode. An astonishing 15.4 miles per gallon.
Ok, thinking....big engine...lots of room to play with gear/speed selection.
Trying to use the ole butt-o-meter to determine best shift speeds was apparently waaaaaaaaay off!

Got home, broke out the trusty owners manual and checked recommended up/down shift speeds.
1 to 2 = 12mph
2to 3 = 19 mph
3 to 4 = 25 mph
4 to 5 = 31 mph

down shifting

5 to 4 = 22 mph
4 to 3 = 16 mph

drop to first below 9 mph


this whole shifting speed on this bike confuses me. Such a large bore engine one would think the shift speeds would be way higher to get the power out of it.

why such a low gear to speed ratio?:dontknow:
It's called "Manufacturer Overkill or Cover Your Assets" By telling people to shift that early they eliminate a lot of warranty work from blown engines. Not that the VTX will blown their engine, but just in case. This is like the stickers you find on hair driers saying "Do NOT use in the shower"

Shifting at those speeds will certainly foul your plugs after a while
 
#5 ·
Would removing nasty science project exhaust and Fi2k going back to factory exhaust affect the gas mileage? Filled up prior to changing exhaust or was my shifting/speeds effecting it?

riding crotch rockets, i would shift in the high RPM range, down shift using engine breaking to slow. I mean i would get on the throttle all the time and i still managed 120-130 miles on a 4.2 gallon tank
 
#8 ·
Would removing nasty science project exhaust and Fi2k going back to factory exhaust affect the gas mileage? Filled up prior to changing exhaust or was my shifting/speeds effecting it?

riding crotch rockets, i would shift in the high RPM range, down shift using engine breaking to slow. I mean i would get on the throttle all the time and i still managed 120-130 miles on a 4.2 gallon tank
I doubt going back to stock or your shifting speeds would lessen the gas mileage as much as you indicate. I'm thinking something else going on here to affect it that much.
 
#10 ·
Ahh, the early models, if this poor mileage just started, I'd look at your fuel pressre regulator first. It's on the throttlebody and if you pull the vacuum hose off it and fuel comes out, it is bad and replacing it will fix that. That will let too much fuel into the combstion chamber. Smell your oil too for gas. If it has any hint of a gas odor, change the oil too
 
#11 ·
Ahh, the early models, if this poor mileage just started, I'd look at your fuel pressre regulator first. It's on the throttlebody and if you pull the vacuum hose off it and fuel comes out, it is bad and replacing it will fix that. That will let too much fuel into the combstion chamber. Smell your oil too for gas. If it has any hint of a gas odor, change the oil too
Thanks for the input Spike, ill check on that soonest
 
#12 ·
Ri


this whole shifting speed on this bike confuses me. Such a large bore engine one would think the shift speeds would be way higher to get the power out of it.

why such a low gear to speed ratio?:dontknow:
Large bore motors, are great for low end torque, the beast probably wouldn't breath very well IF we could wind past the cut off point.

When I'm having fun with her I try and take it up to just below the cut off.
Usually shift at 30, 60, 90.

But when just cursing I'll be in top gear by 30 or so.
02 getting "40" mpg.
 
#17 ·
ahhhhh thats it then. I disconnected the battery to install rear LED signals and to put the diode in the turn signal light under the dash.
OK, so now i have no idea how many miles i got on that last tank. Some relief i guess.

Thanks for all the help guys
 
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