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Old 06-24-2006, 08:36 AM   #1
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Default Poor fuel mileage

Does anyone have any suggestions on getting better fuel mileage? I have an Assoc GT with the stock AE 15 and gas tank and I'm barely getting a 5 min race in before it runs out! I've tried leaning the carb more but then it runs too hot? Any suggestions?
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Old 06-24-2006, 09:20 AM   #2
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If theres enough air getting to your engine then I that is all you can do. Make sure you are running the correct glow plug too.
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Old 06-24-2006, 06:46 PM   #3
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have you tried to close up the main fuel needle on the carb a little. it did wonders for my gt
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Old 06-24-2006, 08:15 PM   #4
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If it is running well on the top end and it seems to continue to get hot then richen the bottom end. When you lean the top end needle you must richen the bottom end needle.
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Old 06-26-2006, 08:22 AM   #5
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Clean the air filter, clean the carb, make sure your needles are adjusted right for both low and top end ( wait until the engine reaches running temp before adjusting ), get a temp gun to verify temps, add some extra fuel line, check your fuel lines, tank, and carb for leaks.


If your running in an area where the air temp is 100f, then you'll have to richen up the settings which will in turn yield crappy fuel mileage.
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Old 06-26-2006, 02:29 PM   #6
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make sure your fuel bottle is nice and tight.... then stick it in a cooler of ice...... only fill your tank up right before you race..... i have to do this with my 21 8p or i will not make a 6min run...... after you have the bottle in the cooler for some time... you will see why it helps.... because the bottle will be all sucked in..... make the fuel more dense...... make it possible to "get more fuel in the tank"
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Old 06-26-2006, 03:39 PM   #7
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its the same volume when its liquid the freezing might separate the oils away from the fuel (not always )and explain on how you get more fuel in a tank when you let the fuel cool not starting any thing or diasagreeing with you(sick of the bs that goes on these forums people arguing about stuff) well maybe a little but would like to know your theory behind this ,couse its not making sense to me well the bottles getting sucked in doesnt explain anything to me except the cooling process settled down the gas fumes and coused a vacum in the bottle just like if you leave it in the sun the bottle expands do to the gases in the bottle reacting to the heat ,remember im just asking and no bs arguing
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Old 06-27-2006, 08:48 AM   #8
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I'm a little confused too as the fuel tank is only so big.

However it still doesn't help him with his poor fuel mileage that he's experiencing. Do what's been suggested in the above posts and reply back with your findings.
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Old 06-27-2006, 11:13 AM   #9
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i guess i cant really explain how or why....... because it was suggested to me from the ofna forum...... but I tried it.... and it works......It does not give you a ton of extra run time......but for me it made the difference between having to pit in a 7min run or not pitting.......I wish i could find the old post....
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Old 06-27-2006, 01:40 PM   #10
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Steve uses magic fuel! He can't explain it, otherwise he'd have to kill you. Magicians never reveal how they do it, they just show you the result!

Just joking, Steve knows what he's talking about, he's not full of hot air, or cold fuel for that matter!
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Old 06-27-2006, 04:21 PM   #11
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The compression of the bottle you're seeing is the air trapped inside of it compressing because of the lower temps. Try filling your fuel bottle absolutely chock full, then throwing it in the cooler again. I'll bet you don't see the bottle collapse in that case.

Double check your drivetrain too. Make sure there aren't any blown out bearings, that the brake releases fully when you grab the throttle and that your rear wheel bearings don't bind when you tighten the wheel nuts down.

Double check your low speed needle setting too. Here's the best way I've found yet. Run the truck until it's up to temp, then come to a stop and idle for 5 seconds. Grab full throttle, and see what the truck does. If it spews a ton of smoke, and stumbles over itself before clearing out and taking off, it's too rich. If it takes off immediately like it does when you're already rolling with little or no smoke, it's too lean. If it puffs smoke and just BARELY stumbles when you grab the throttle, then you're on the money.

The low speed needle being off has bitten me in the past. If you're too lean on the bottom, you end up adjusting the top too fat to compensate, and your fuel mileage goes down.
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Old 06-27-2006, 05:36 PM   #12
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Air is most dense at 4*C, or about 35*F. Liquid is the same.


Run your real car in the dead of winter. What happens? If you're on the highway, you get a few extra miles on the tank. That's only if the heater was off of course. The tempature of the ignition chamber does play a role in the fuel mileage. When the temp around my area is right around 10*C, I get about 600-650Km's per 100L tank. Or about 400miles to 25 gallons, roughly. Bump that temp to 25*C, I only get 500-550Km's a tank. Air temp and fuel temp play a huge role.

I don't know the the exact sciences in this but it is something we learned about in trade school (I'm a gasfitter by trade).
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Old 06-27-2006, 05:59 PM   #13
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you know its starting to make sense a little,im going to try it ,my fridge is set a 37 degrees and ill measure the fuel i have stored in garage and see the difference in running time ,shoot if it works i might have to bring a cooler with me to the races lol,so its not that more fuel fits in the tank couse it should be the same volume right?its couse the fuel is more concentrated at that temp of the fuel ,i guess the outside temp would play a big role on that also .for example if it was 50 outside and you used the cooled fuel the time would differ if it was 90 out correct
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Old 06-27-2006, 06:08 PM   #14
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In theory, yes. In practicality, and in my experience, yes. I know others have had different results but it has worked for me. Sometimes as much as a minute a tank. Not alot but in a 45 or 60 minute race, that could wind up being half a lap or a lap.
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Old 06-27-2006, 06:19 PM   #15
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exactly a minute is alot ,and 2 and a half laps on my track .no dought i will try it tomorrow and post results .
ill let the buggy run dry and blow the fuel out of the line so theres no contreversy in the results
edited it coused i checked my lap avareage time from the last race and it was 23.4 so dam thats a huge difference
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