Terrible gas milage

slowspree · Post by **slowspree** » Mon May 07, 2007 10:52 pm

I have my engine running really well but I have put about 20 miles on it with a full tank of gas and now its nearly empty. What could be causing this??

-aL- · Post by **-aL-** » Mon May 07, 2007 11:13 pm

check for leaks

chevyguyjay · Post by **chevyguyjay** » Tue May 08, 2007 2:34 am

wow!

edoggdoremus · Post by **edoggdoremus** » Tue May 08, 2007 3:34 am

i have the same problem with gas mileage too. I've checked the needle setting (was set running rich), main jet, and cleaned the air filter, but it really didn't have much affect on the mpg. cylinder and exhaust port are free of carbon deposits. What do i check next?

slowspree · Post by **slowspree** » Tue May 08, 2007 10:47 am

Could not having a fuel petcock affect mpg's?

Also, how many turns out is the needle setting?

Streetglow · Post by **Streetglow** » Tue May 08, 2007 2:28 pm

I'm getting really poor mileage also at the moment. I wonder if I need to disassemble my carb and clean it. I'm getting roughly 40 miles a tank which is about half what I should get.

Gamemedic · Post by **Gamemedic** » Tue May 08, 2007 2:55 pm

Am I wrong or is that good. A spree tank is only just over 1 liter, there are 3.79 liters in a gallon. That would give you 60-80 mpg......not bad.

Streetglow · Post by **Streetglow** » Tue May 08, 2007 3:36 pm

the spree tank is 2.5 liters or 0.66 US gallons and should give you 50-80 miles per tank, so per gallon that should equal 75-120 mpg.

I'm almost certain my poor mileage is due to my carb being varnished, everything else has already been ruled out.

hemlockz · Post by **hemlockz** » Tue May 08, 2007 4:03 pm

slowspree wrote:Could not having a fuel petcock affect mpg's?

Yes.... due to gravity all of your fuel will drip down the fuel line into the carb and fill the bowl then slowly drip out the overflow. Unless you have a petcock valve.

edoggdoremus · Post by **edoggdoremus** » Tue May 08, 2007 8:34 pm

my carb is leaking. very slowly when in idle but when i rev it it increases, and im sure it leaks even more when in full throttle. Seems a lot of leakage is around the base of the airfilter tube. Could this be a bad gasket? I took the carb apart last week and the float seemed to be working correctly

Post by **noiseguy** » Tue May 08, 2007 10:05 pm

Dirty carb... likely a non-closing float valve. You should fix that.

I actually have a "Increase MPG" post under tech docs. Go read.

PimpinSpree · Post by **PimpinSpree** » Thu May 10, 2007 7:17 pm

i have the same problem, i get roughly 50 mpg. I had a free flowing petcock, and just put working one on, we'll see how much it helps