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]

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.

 

[skid jackson]

my tubes are routed up to the air box...

 

[Eric K]

I would caution on routing the overflow tube (the one from the bottom of carb) up high. If the float bowl overfills the fuel can then start draining down into the engine.

With a float set correctly, the only attitude I can find where fuel will drain in normal operation is downhills steeper than 30 degrees. I have not found the limit on uphills. When cornering the centrifugal forces pull the fuel out so the angle of the fuel is reasonably close the angle of the carb. The carb should not drain out the overflow on a stationary motorcycle leaned over to at least 20 degrees.

 

[jimbolaya]

Use a "Dial-A-Jet". It will give much better gas mileage. I use one on my 03 ktm 200exc.

 

[2 strokes 4 life]

Does the Dial-A-Jet really do what it says it can? I have been really interested with this product espicialy seeings how i am going to make my bike street legal, and the changes in alititude will be great.

 

[stay_upright]

Never got more than 60 on my 300.

Never got less than 60 (unless racing) on my 300??? I do 3 hours racing without hitting reserve...

 

[stay_upright]

And uphill too!
The bikes would probably do 50 mpg with Fi

I get about 50mpg trail riding. Only a TTR 250 was using less fuel than me this weekend.

 

[2 strokes 4 life]

My bike in comparison to RM125, RM250 (huge tank), and a YZ250 my bike always goes longer then there bikes do.

 

[skid jackson]

did 30 miles at a snails pace, 1st 2nd gear just off throttle and gas was just under the 3 liter line. thats about 6.5 liters for 30 miles all low throttle. doesn't seem like very good mileage to me!!

 

[kim]

This "Dial-A-Jet" sounds interesting. Any idea on cost ?

I wonder if you could run your float level a fair bit lower and then it be compensated by the dial-a-jet ?

This would somewhat eliminate the "spillage" from the carby

K

 

[2 strokes 4 life]

http://www.thunderproducts.com/dial_a_jet.htm
It costs $75 you can also have a dual system for $150 i think. Look around the site, there are many cool products.