Low gas mileage!

[AaronF]

I am having problems with two of my bikes only getting around 30 miles per 1/2 gallon tank of gas,very odd if you ask me.I weigh approx.150,6'1 height 44T Sprockets on both 26" Bikes.I do run them at full throttle most of the time on the longer roads,it is mainly flat land here in my area.Everything is stock on both MB's besides the aftermarket air filter on one MB.I've checked the spark plugs on both,one of them is half brownish and the other one is just a bit oily/rich..What could be the problem here? Any help,I'd appreciate it!Thanks

[george_n_texas]

Could you have a fuel leak? Does seem mighty low mileage for sure.

[Charged-Reacter]

I have 2 bikes with 69cc engines and I am using 40T sprockets. One engine
is straight sparkplug style with the old style carburetor. I run at full throttle on this
one most of thev time. I get gas milage like yours.
One bike is the slant head plug with the new style carburetor. This bike runs
about equal in speed at half throotle and scares me at whole throotle because
I am running with a rag style sprocket adapter. I am also seeing alot better mpg
with this one.
Do you think that it might have something to do with the carburetor slide?
For some reason the new style carburetor has alot more throotle than the old style
carburetor that I am experiencing.

[AaronF]

The carburetors seem fine,no sticking or anything.Sorry I forgot to mention..Both bikes are 2-Stroke 66cc one is a slant head and the other is a straight Raw.My buddy and I experienced this riding a 30 mile ride,country roads and some slight hills the other night but didn't expect to only get 30 miles out of a full topped off tank.Full throttling or not,it seems these should be getting much better than 30 or so miles..Thanks for your reply Charged!

[2door]

Aaron,
You didn't say how long these engines have been running. As you've probably read here before they get better with time. Both power and economy will improve as the rings seat and the engines get some miles uder their belts. Obviously running WOT constantly will decrease your milage; just think how your car would respond to that. Back off on the throttle a little, give the engines some time to be fully broke in and see what effect that has.
Tom

[AaronF]

They both have been ran 400+miles.I am mixing at 32:1 gas/oil with cheap synthetic oil.When I'm just riding around town my speed averages 10-25MPH witch most of the time I am cruising around town..On longer trips I ride at WOT for awhile and then let off giving it a nice cruising speed.

[captainrichhill]

run less oil=more gas per tank=better gas milage(to a point)

[Cabinfever1977]

wow,i weigh 120lbs and ride at wot around 30mph and get 90miles per tank which is 180mpg and i running 32:1 with reg cheap oil and all stock except i have a air pipe with just a screen for a filter. 44t sprocket 48cc starfire engine reg head

maybe your idle is turned up to high,try lowering it til it starts to stop and then turn in a little,enough just to keep it running and u will see better milage. also clean or replace your airfilter. clean your sparkplug too.

[Maxvision]

I met a guy who rides close to 70 miles a day. He's retired and dying of cancer so it's what he does to keep entertained. He's got the big tank and carrys 2 spare bottles of gas (about the size for a small Gator-aid bottle. He says he goes through all that gas every day. He says he gets about 70 mi. to a gallon of fuel.

He's a big guy, well over 200 lbs with a regular 44t sprocket.

Hope that gives you some insight.

[AaronF]

Thanks for all the replies! I have one more question..My fuel valve broke into pieces the other day and I'm not quite sure the correct size OD 1/4,ID fuel inlet would be 1/8 If I am correct? Has anyone tried a replacement such as this Fuel shut off and filter 1/8" pipe thread, 1/4" nipple - eBay (item 350279726985 end time Dec-15-09 15:24:33 PST)