20 mpg

[skid jackson]

06 300
42 pilot
air screw 1.25 turns out
cck needle #2 slot
#7 slide
180 main

I put exactly 1 gal of 50:1 in my bike tonight. Ridng at an average speed of 17 mph in semi tight woods riding mostly a gear up at moderate pace I hit reserve at 15 miles. reserve is 1 liter I believe so call it a quart. that would mean I got about 20 mpg which would give me about 45 miles at a moderate pace. this seems pretty crappy to me .... carb does not appear to beleakign or anything like that. Is this about right?? too low??? I shudder to think what Iwould get I would get in race mode.. 30 miles out of a tank?? I'd prefer to get about 60 miles out of a tank. word

[mountain thumper]

i know what you mean, i went out on monday night, road apprx 5 miles in, to the trail head, then another half hour before i had to limp home. the 2 guys i was riding with were on big bore quads, and they were at half a tank when i was switching to reserve, and they rode about 10 miles of road before i even unloaded.

[Cruiser]

On my 03 I would get about 55-60 racing in tight woods. On open roads I could get closer to 80..

[iancp5]

Never got more than 60 on my 300.

[eff]

I'm good for about 55 miles before I hit reserve.

[Eric K]

A few observations on increasing fuel efficiency...

1) Float and Jetting – this is the first step. Make sure the float is set correctly. Dial your jetting in so the plug looks good, the engine runs smoothly across the range with good power and throttle response. The tail pipe should have little oily spooge when you are jetted well.
2) RB designs head mod. This will reduce the amount of unburned fuel and improve power (primarily low to mid) by improving combustion efficiency.
3) down hills – the PWK carbs will drain fuel out the overflow when you are descending hills steeper than about 30 degrees. I first noticed this when following my oldest son down hills. I set the motorcycle up suspended at a downhill angle and found when the fork tubes were near vertical the carb would drain lots of fuel out the overflow. This is with the float set to spec. This becomes noticeable on long (1/2 mile to 1 mile) steep descents. Minimize your time on the descents and/or shut off the fuel and down hill mountain bike the ride.
4) riding style – maintaining corner speed with a smooth flowing style notably improves efficiency.

On technical trails I get 30+ mpg riding alone. I ride to maximize cornering speed. I weigh about 270 lb geared up.

I get about 22-25 mpg on the same type of trails giving my 6 year old son a ride. He weighs about 95 lb geared up. We corner slower and use more fuel accelerating out of corners. There is also more fuel used due to the added mass.

[iancp5]

Originally Posted by Eric K

A few observations on increasing fuel efficiency...


3) down hills – the PWK carbs will drain fuel out the overflow when you are descending hills steeper than about 30 degrees.

And uphill too!
And over sharp bumps - try leaving the fuel tap open on the trailer and drive along a rough forest fireroad.
Not to mention falling off
The bikes would probably do 50 mpg with Fi

[skid jackson]

ian ....
isn't there some kind of vacuum action going on when the motor is running so the carb won't be pissing fuel out will your riding along simply from the bmps??

[mountain thumper]

thats what i always blamed fr my mileage, the piss tubes. ive parked, wolked off to answer natures call, and come back to find my tank is almost completely empty after the stand sank into the dirt a few inches and the darn thing overflowed everything. the gent i got my ltr stuff from, says that rerouting the gas lines to the aribox help with this and stopping h2o from getting to carb thru drain lines.

[eff]

Sounds like the float needs to be adjusted.