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  1. #1
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    Nitro 4-Tec Not Starting?

    I'm sure there have been tons of threads about specific problems as to why the Nitro 4-Tec won't start in certain cases, but I could not seem to find a solution to this. The car has not been able to start for a while, maybe 2 weeks. When priming the engine with the gas line empty, I noticed the fuel was moving VERY slowly. When the fuel made it to the engine nothing happened, I lifted the car off the ground, primed it and the wheels moved but it did not start. I put nitro directly into the glow plug hole and he car started for a few seconds and cut off. Any ideas?

  2. #2
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    Could be a couple of things possibly as simple as out of tune or I'm thinking the carb is blocked somewhere. If you can take the carb needle out and check for gummed fuel or some other obstruction. You said the fuel moves very slowly? can you remove the fuel line from the tank and blow thru it to the carb. with the carb open, full throttle you should be able to get a steady stream of air without too much effort. It will have some restriction, but not like your finger is blocking the other end or the hose is kinked. If that is fine, check the fuel tank for the same thing. just do the opposite. It could also be the exhaust pressure line. You have a few things to check. It obviously starts.. so the plug and engine are fine. Let us know how you make out.

    You also mentioned the cars wheels turn with the car off the ground when priming it? They shouldn't move until the engine reaches proper rpm's to engage the clutch. Have you checked the clutch as well, or am I misunderstanding something here?
    Last edited by cenracer1; 02-05-2013 at 05:26 PM.
    Maxx3.3/ rusty5700/ slash3800/ slash5700 /4tec3.3

  3. #3
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    Well, the fuel is suppose to move up the line quickly but when priming it the first time with no fuel in the line you can see the fuel move up the line as if the line is being squeezed and only allowing fuel threw slowly. Not sure why the wheels spin, it's not fast it's just a slow spin only when it's off the ground. Could it be that the engine is getting fuel, but not fast enough at a time that it moves the wheels slightly but doesn't start the car? I actually took out the air filter and primed the engine when I knew there was a little fuel in there, I put my finger over the carburetor, blocking air, then moved my finger which led the car to starting for a few seconds then cutting off. Not sure what to do.

  4. #4
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    Not sure what you are using to start the motor with. I like the ez start as it works well. what I do is put my finger over the exhaust stinger and push the button. The fuel should go into the carb at a rate of about 2 inches per second..its not blazing fast when starting. IF its slower you have a block somewhere.when starting engine there should not be wheel spin at all, its not turning over fast enough to engage the clutch. You have I would guess a broken spring or hung up clutch pad. check that before anything else as this will prevent the car from starting. let us know what you find.
    Maxx3.3/ rusty5700/ slash3800/ slash5700 /4tec3.3

  5. #5
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    Thanks for the help, cenracer1. I got it to start. I took apart the backplate and made sure are the lines and hoses where adjusted properly then went ahead and adjusted the carburetor. I got it to start easily at this point, however after it starts it finds itself revving to high RPM's then slowing down and cutting off on it's own or when I give it throttle. Any ideas on this problem?

  6. #6
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    Sounds like you may be pulling air some where. Make sure your tank is sealing good and that you don't have any holes in your fuel line.

  7. #7
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    Sounds like either an air leak somewhere I would check the backplate... not sure why you took that off in the first place. They are known to leak if messed with too much. The other thought would be too lean, but an air leak does the same thing. Are you seeing air bubbles in the fuel lines leading to the carb? If yes replace them.. for the back plate, check and make sure the seal is good.. there should be an o ring or a gasket of some type.. Its been a while since I opened a Traxxas motor and make sure they are good and sealed. let us know...
    Maxx3.3/ rusty5700/ slash3800/ slash5700 /4tec3.3

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