Fuel consumption vs RPM vs throttle setting?

**dynamite9585** · 13th September 2010, 13:54

ok, my fuel consumption on the open road isn't quite where i would like it yet.
a carb clean and a tune took me from 13km/l to 17km/l

on the open road in 6th it's bloody hard to keep it at open road speed. i need to be holding almost full throttle just to maintain speed.

put it in 5th or 4th even i can ease off on the throttle a fair bit but rpm is increased bt 1-2k RPM.

what one is more likely to increase my range?

**imdying** · 13th September 2010, 14:00

Originally Posted by dynamite9585

on the open road in 6th it's bloody hard to keep it at open road speed. i need to be holding almost full throttle just to maintain speed.

Something is well up with that then.

Originally Posted by dynamite9585

what one is more likely to increase my range?

Larger throttle openings use larger amount of gas.

**Gibbo89** · 13th September 2010, 14:02

Originally Posted by dynamite9585

ok, my fuel consumption on the open road isn't quite where i would like it yet.
a carb clean and a tune took me from 13km/l to 17km/l

on the open road in 6th it's bloody hard to keep it at open road speed. i need to be holding almost full throttle just to maintain speed.

put it in 5th or 4th even i can ease off on the throttle a fair bit but rpm is increased bt 1-2k RPM.

what one is more likely to increase my range?

17km/l is about the norm for an inline four 250 i reckon

**dynamite9585** · 13th September 2010, 14:04

Originally Posted by Gibbo89

17km/l is about the norm for an inline four 250 i reckon

my g/fs CBR gets 23! i expected range to me closer to 20 even if hers is better than average

**MSTRS:Me** · 13th September 2010, 14:08

They are all different as far as consumption is concerned, BUT full throttle to maintain 100kph is WRONG. Something needs sorting there.

**Gibbo89** · 13th September 2010, 14:14

Originally Posted by dynamite9585

my g/fs CBR gets 23! i expected range to me closer to 20 even if hers is better than average

be interesting to see if an 88 to 90 cbr owner could compare to 23. they got a bit more high performance after the 86/87 ones i think

**quallman1234** · 13th September 2010, 14:16

Perhaps you could go for a large rear sprocket?

I know some guys who race cbr250's at manfield, run quite short gearing compared to standard and still only just get into top. Obviously you don't want it to revving its balls off.

**porky** · 13th September 2010, 14:17

are the sprockets (both) standard? By what you say the motor revs out ok, but bogs down in 6th?

**dynamite9585** · 13th September 2010, 15:36

Originally Posted by porky

are the sprockets (both) standard? By what you say the motor revs out ok, but bogs down in 6th?

as far as i know both sprockets are standard.
it doesn't bog down so much, just starts to wash of speed.

just went out for another ride, it's not full throttle to maintain it, just a little over half. will put some markings on my throttle so i can get a better look

**Gibbo89** · 13th September 2010, 15:38

quite the perfectionist aren't ya dynamite?

**dynamite9585** · 13th September 2010, 15:43

Originally Posted by Gibbo89

quite the perfectionist aren't ya dynamite?

yea i get mild ocd.
then i get really pissed off, think fixing it is too much hassle and just live with it

**Gibbo89** · 13th September 2010, 15:44

Originally Posted by dynamite9585

yea i get mild ocd.
then i get really pissed off, think fixing it is too much hassle and just live with it

like most of us... haha

**Juzz976** · 13th September 2010, 16:47

Fuel consumption = rpm² x displacement

5.88L / 100k Sounds about right, 250's are not as efficient above 70km/hr because of too much rpm.

You'll probably find it will want to sit at 110-120 in 6th and 100 in 5th, depends on bike tho most have a sweet spot 4 each gear. The TL1000R I want to get likes 120 so I might have issues with the Demerit regulator.