Gas Mileage

[mikemoto]

At the national enduro this week I ran out of gas twice. After going to reserve and kicking 10 times the bike finished the section's but on fumes. My f-250 got better gas mileage. After 25+ miles at the end of the day there was about 1 inch of fuel in the tank. I will check the float bowl level today. What kind of mileage are you guys getting on your 2011 250s? Other then that and a front brake lever coming loose with 5 miles left of one section (I had to keep pressure on it to keep it from falling off) the bike ran great. This is the first bike I have had in a long time that the suspension has not been sent out on yet. My last bike had ttx front and rear. The forks will probably go out for the mid valve mod. The gas thing has me concerned. I dont really want a big tank.

[Clay]

Mike,
There were three Gassers on my row and we all made it with no problems. Last fall at the last National Enduro in IN I had a small piece of plastic that came out of the tank and lodged in the carb, causing the float to stick. Of course, gas was pouring out of the vents and I could only go 20 miles before going on reserve. Check that and your float level, too.
Clay

[ScottyR]

I went 37 miles on a tank in Sumter and had about a litre left in the tank. I was on reserve that day.

I would check the float as well. 25 miles is way off the norm.

[mikemoto]

I know something isn't right. I will look at it today. What should it be at? Is it in the manual? I haven't looked yet

[Robby45]

I ran out 1/4 mile past the last check at Sumter (~32 miles total). I had fuel leaking from the gas cap. I have since tried 2 different vent tubes (one with an additional check valve and one very long tube bent up to prevent leakage). Neither of these worked and I was still losing fuel throught the vent at Sandlapper. I have checked my gasket in the cap about 5 times now and everything looks ok. I hear a check ball rattling around in the cap and it sounds like it has a lot of area to move around in - not sure if it should be doing that.

I have heard several other people on this forum and at the races having this issue.

[GMP]

There is a check ball in the cap, and you should be able to test it by pulling air through the vent and tilting the cap. Maybe something like plastic debri or mold flashing is blocking the ball from sealing. Pull the rubber seal out, and pop off the bottom inside off the cap (with three small holes). You should be able to see whats going on from there.

I had the opposite problem where the rubber gasket swelled and blocked the vent holes, starving the bike for fuel. I cut the center of the gasket away from the vent holes and enlarged the holes, no more problems. Same thing happened to Fred Hoess once, and talking to his mechanic, they also found the ball sticking closed. They replaced it with a smaller ball, but I did not see the need. Keep your eye on this though.

[Moab GasGas]

Same here had to reset the float and get the plastic out of the tank clean the carb and all has been good since

Originally Posted by Clay

Mike,
There were three Gassers on my row and we all made it with no problems. Last fall at the last National Enduro in IN I had a small piece of plastic that came out of the tank and lodged in the carb, causing the float to stick. Of course, gas was pouring out of the vents and I could only go 20 miles before going on reserve. Check that and your float level, too.
Clay

[Tlineman]

Bent the metal tab that the needle hangs from. You have to hold the carb at an angle so as the tab is contacting the spring in the needle, but not depressing it. My carb was set at 6.5mm from factory, I've lowered the float to 8mm, so therefore less fuel in the float. Only ridden the bike once as I'm waiting for snow to go away but I thought it was a thirsty machine. Checking Keihin's website they list a float height of 6.5 mm for a 38mm PWM carb. I assume that this is the factory spec for ASII. Didn't have any starvation issues on the one ride.

[Dave]

My YZ has an AS2 - this is from the Yamaha manual.