What plug are you using? I would recommend using OS #3 or #8.

Try this:

1. Reset the needles back to factory settings....High speed needle should be at 4 turns out from stop.....low speed needle should be at 2 turns out from stop.

2. What fuel are you using? What percent of nitro? Is it fresh / new? If not....buy some fresh fuel.

3. Is your carburetor seated all the way down onto the engine? The small lock nut came loose on mine and caused similar problems as your having. Check for proper seating and tight nut.

4. Is the lid on your fuel tank sealed tight? To check for air leaks in the tank....remove both fuel lines...tank emptied....pinch the line going to the carb....now blow into the line removed from the exhaust. Listen for air leaking....or the ability to actually blow air through the fuel line.

5. Have you run the engine without an air filter....ever? If so...is it possible that you have dirt in the needles? Just a thought.

6. Is this a new rig? Is the clutch ok?

7. Have you adjusted the needles "ONLY AFTER" the engine is fully warmed up....then made the adjustments?

8. Changed out the fuel lines in the event of a pin hole leak?

Keep looking....if it's not a defective engine from the manufacturer....then it's something going on with one or more parts of all that makes the engine run and work. If you cannot find the problem...then give Traxxas a call. I hear they have excellent support and it's a toll free number.


Good Luck!