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Several things to check.

First thing I would check is your idle screw, you may need to open this up a bit. Also, your servo may be applying too much pressure when braking, where the arm is actually pushing the motor. Sometimes either full throttle, or full brake you will actually see the motor move.

You can adjust this on the transmitter to some degree, or you may need to move the servo arm position. Not sure if that is an issue on the T-Maxx, I do know we usually adjust the idle screws after the first couple of tanks on them.
 

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The first thing to check is the carb barrel gap like LoneSA said. Make sure that at the fully "closed" positon the ga[p is about 1mm (thickness of a credit card). It's adjusted by a screw. Moving teh screw clockwise will open the gap, counterclockwise will close it down. do all this with the throttle linkage disconnected. When it's right, reconnect the throttle linkage and adjust it so the carb barrel comes all the way to the closed position at idle. If you don't, then when you hit the brakes it will close the gap all the way and your truck can die. It also sounds like the engine might be a little rich if you're having to give it a bunch of ga to get it started. What are your engine temps?
 

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Could this be a too lean issue? Or too rich? Rich you would idle it up pretty well to keep the engine running at low speed, and then it would stall when you hit the brakes. Lean would it would stall at high temps, but be ok for the first few minutes (when you hit the brakes I mean).

Is it hard to start, or does it take the usual 2.5 seconds?

Have you adjusted the needles, or are you still on the factory settings?

Edit: CJ was posting at the same time, I agree that it does sound like a rich issue.

Anyone have needle settins for a T-Maxx 2.5? I am trying to remember, 3.5 on the high, and leave the low at factory settings. Well let me go look instead of guess... Ok try 3.5 turns on the high, most likely you are at 4 turns. If you need more help just ask us, we are by far the most rude and friendly-helpful bunch of stupid, but yet smart RC guys. Just don't listen to what any of say... :)

The T-Maxx is a fun truck, takes a beating well, so you will be happy with it once it runs right.
 

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Discussion Starter · #6 ·
cjtamu said:
The first thing to check is the carb barrel gap like LoneSA said. Make sure that at the fully "closed" positon the ga[p is about 1mm (thickness of a credit card). It's adjusted by a screw. Moving teh screw clockwise will open the gap, counterclockwise will close it down. do all this with the throttle linkage disconnected. When it's right, reconnect the throttle linkage and adjust it so the carb barrel comes all the way to the closed position at idle. If you don't, then when you hit the brakes it will close the gap all the way and your truck can die. It also sounds like the engine might be a little rich if you're having to give it a bunch of ga to get it started. What are your engine temps?
I dont know the temp I havent ran it in a wile and when I have it hasnt been long enough to tell.
 

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What does it sound like then? When it's running does it sound like it's sputtering? Go ahead and set the barrel gap and readjust the linkage b/c you'll never get it tuned right without doing that. Then fire it up and see what it does.
 

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Discussion Starter · #8 ·
It sounds like it's wound up at high rpms,and the idle needle can be backed all the way out and it will still do that. I have to ajust the idle at the controller like the idle screw doesn't even have any effect.
 

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If you can adjust the idle using the radio trim then the high idle doesn't have anything to do with the engine tune. It sounds like a linkage problem that's not letting the barrel come all the way back to closed at idle, but when you move the trim the servo moves so then the barrel can close. It dies b/c when you hit the brakes b/c it closes all the way down. could be the spring, most likely the rod collars need to be adjusted. Set your linkage like I said above. Set your throttle trim back to center first, loosen teh collars, then turn on the radio and car. Then set the linkage so teh barrel is closed at idle.
 

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Discussion Starter · #12 ·
The thing is that I have to open the throttle for it to even start,and when I get it started I can't idle it down by the idle screw or by the throttle trim or it will die ether way. A wile back one of the screw on the side of the carb by the high speed needle came off and I lost it and the threads where striped so I supper glued a little peace of rubber over the hole and it has ran like this ever since. I would take it to a hobby shop or a local guy that works on R/Cs, but the last time I did either I got it back the same way even though that was trany problems and this is engine problems.
 

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Sorry did not read the last post, my browser did not update. An airleak is a possibility describing the work you had to do to the carb. We need to find you a carb, it might not be something that you can tune correctly depending on what is going on inside the needle passage, etc.
 

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Huh, where did my post go? I left one yesterday that said we need to find a new carb. Not sure which ones will work on that engine? Can you run an OS CV/CV-R carb (10E/ER or 10C) on that engine? I have a NIB Dynamite rotary carb that's the same size as the OS, and I might have a 10C slide carb. If they'll work I'll send one to you. If anybody knows it they'll work, post it up.
 
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