Hey everyone,

I'm running a Duratrax Axis, and I've got about half a gallon of fuel through it so far. I'm enjoying running it around, but it has a peculiar behavior, at least for a noob like me. So please don't give me too much grief if this is a simple problem.

It idles fine, and revs just fine up to about half throttle. If I pull the throttle past that point, it will run at the same RPM as before for a couple of seconds, and then it sounds like it bogs down. If I let off the throttle, it goes back to running just fine at that original RPM.

Any ideas? Thanks in advance.

Is the engine just new or barely broken in? After you follow the manual for breaking in the engine that came with your car, you will need to adjust the high speed/low speed needles to bring the performance up. From the factory the engine is set for break in performance. After break in you can start to adjust the needles. Just follow the instructions that came with the Axis.

Be careful on the adjustments though, a very small turn of the needles go a long way, and too much can cause your engine to overheat and shut down.

Good Luck!

Do you think the high speed needle is too rich?

I have tried tuning it, and have it close to the 2.5 turn lean limit that Duratrax suggests in their manual.

Thanks again!

It sounds like the HSN is too LEAN. Turn the HSN CCW in 1/8 th turn increments until the engine runs at top speed without "bogging-down".

If it ran before at the same setting and never got touched and now it boggs you 1st need a fuel filter and 2nd need to get the clog out of your needle.

If its a single needle carb and you turned the needle more than 1/8 to the right then the engine will overheat a begin to die. Try to set the needle back to its stock position and see if it runs fine from their. Then you can make your adjustments.

Hey Krusty how do you get the pictures on here on the forum?Or post?

Check the air filter then if you have a fuel filter check that. if both of those are OK, then is sounds like you have the high needle way to lean. I had a motor like that and it confused me. It sounded like it was starving. I richened up the motor and it ran fine.

I'm having the same problem.

Only I did richen it.. but it didnt help?!
I have a 3 needle carb and also have a post on this.

ram

I believe the LSN is too lean and the HSN is too rich try 1/6 of a turn on each and see where that takes ya.

I originaly had this problem with an MT12. I had the high end needle set way to lean. When I had to richen it, I had to turn it out 3 turns. I know that this sounds like a lot, but I went from 2 1/2 turns to 5 1/2 turns and the motor ran like Sadom.