brian8474

I have an Ofna Hyper 7 TQ sport with the mach .28. I just finished the first gallon of fuel which was o'donnell. I stopped at a different hobby shop closer to home and bought the Traxxas top fuel 20% same nitro as the o'donnell. Filled the tank and ran it around the yard for a couple of minutes and then it started running a high idle as if it was leaning out? I found a hole in the fuel line near the carb. Changed out all the fuel line with new, Checked that the head screws were tight, Checked the exhaust gasket and spring for a secure connection, i have reset the carb to factory and none of these thing have helped. The problem started with the fuel change...? Should i get some o'donnell and trash the Traxxas? This problem really has me stumped. Thanks in advance for any advice that can be given

Thanks,
Brian

Argess

I'd chalk it up to the different fuel. Although the nitro % might be the same, the oil% might be different. Just re-adjust your tune a little bit and it should be fine. Or go back to your old fuel.

For the idle:

If the idle is staying high and not eventually dropping, try richening the LSN a bit. If the idle is high after a WOT run, and then eventually drops, richen your HSN a little bit. Soemtimes a bit of both can help.

High Speed:

Don't forget your HSN for high speed running with the different fuel. It may be running a bit lean too. Look for a smoke trail and make sure the engine isn't screaming too much.

nitroexpress

It doesn't matter what engine you run, Traxxas fuel is not a good idea.

brian8474

I have tried all of the above and its still doing it. I will get some o'donnell fuel and see if it changes. Ihave been out of the hobby for several years but the tuning has always been easy for me. I had a tmaxx back when they first produced that model and then i have had 2 ofna buggies since then this is my third after a 3 year break. I guess fuel isnt what it used to be.? I was pretty sure the different fuel would call for a tuning adjustment but the way its acting i think there may be air getting into the system somewhere...?

jmaxey51

+1 .... O'donnell fuel IMO is the best fuel out... and if you switch to any other fuel (from my experience) you will have to richen both the bottom and top needles, OD Race blend fuel has 8% oil and the new Speed blend has 7.5% oil which makes it so you can run the engine much leaner so switching to other fuel (traxxas has like 15%+ oil) it will act very lean... the more oil the hotter the engine will run, making it act leaner.

subbass

My Feedback: (13)

Never use fuel color dye in it,If you ask me I consider color dye a contaminant and does lower engine performance.I notice some fuels have more dye in them than others,Still the best fuels are the ones with no dye in them at all like odonnel and sportwerks.

rccheech

O donnell or Byrons race fuel, cannot go wrong with either one, my personel preferance is Byrons race gen 2.

brian8474

The byrons at my hobby shop says its for airplanes?

nitroexpress

Obviously, you wouldn't useairplane fuel in a on/offroad vehicle.

http://www.byronfuels.com/pages/products.html

brian8474

Kinda figured that..

brian8474

Thanks for the help guys, I will get some OD fuel this week sometime and see how it goes. I will post the results.

Thanks!