Fix For Traxxas 3.3 Nitro Engine "Won't Idle" "Can't Keep Engine Running" Stalls, Will Not Start. 

I thought I was going crazy when they said set to 1mm gap but it would idle if I held it there this was a great fix for faulty craftsmanship.

Thank you for your comment. I’ve checked the piston and it’s correctly fitted. I believe if the piston was fitted in reverse it would never start. This is because the piston is cut to allow the exhaust fumes to escape. If fitted the other way the fumes could not escape through the exhaust outlet.

Hi there : that dia oil seal is made out of metal , or is it metal? And what is it that dia oil seal your using?

Hey where is the idle screw located on a 3.3?

piston cut must see front. back side(facing exhaust) must be flat. you must reverse your piston front back. you could start your engine opposite way but it will not idle easily, not setup easily but could work

RE: Tuning woes with REVO 3.3 The operating temps should be at 270ish, I run my engines at around 245-280 depending on the day. here the guide, I’ve just copied this from a file on my computer so sorry if there are some inconsistencies with your problems. (I’ll share this around. Cheers) now, for the idle being too high or too low, first set it back to factory which is 4 turns out on the high speed needle and 1.75 turns out on the low speed, start the truck and run it around to let it warm up, once you have it warmed up bring it in and let it idle, if it's to high you will need to turn the idle screw out maybe 1/4 or 1/8th of a turn, and see how it's idling then, if you can’t get the truck to start, give it a little bit of throttle, once the engine is warm it should start up very easily. then one you have it idling you can start tuning, when your tuning, go in very small increments at a time, and ALWAYS tune the high-speed needle first, I usually go by 1/12 or 1/16th of a turn at a time, but must guys go 1/8th of a turn, after each adjustment do a few high-speed passes, take very careful note of 3 things. 1. the performance, has it gotten better or worse? when you start getting the rpm up does it sound like it's cutting out? if it sounds like it's cutting out then you are to lean and need to richen the HSN, if it is loading up and the performance is very sluggish then it is rich and you can go a little leaner 2. the smoke trail, there should always be a nice, clearly visible trail of blue smoke coming from the exhaust, always, if you cannot see a good trail of smoke, it is another sign of being to lean, if you’ve a lot of smoke at all rpms then you can go a little leaner 3. the temperature, since this is your first nitro truck it is a good idea, you get a good, reliable temp gauge, the engine should not go over 270 degrees F, if it does it is another sign of being to lean and you should richen it up just a little bit, but something most people over look is that you should not run under 190 degrees, if you do the piston sleeve doesn't expand enough and the engine will wear out very quickly. a last note on the high-speed needle is, never tune by one symptom alone, never tune just by performance, or smoke trail or temp, use at least two, so if you lean the engine out and the temps go from 220 to 230, and you note it's a little more powerful and go a little leaner, the only time you should ever tune by using just one symptom is when: A: you run to lean and the engine start hesitating and cutting out B: the temp goes above 290 degrees F in both cases you need to richen the HSN by at least 1/8th of a turn if not more. now for tuning the low-speed needle one the high-speed needle is set to where you want it, you can start with the low speed, start off at the factory setting, and just like the HSN tune in small increments of at least 1/8th of a turn, if not smaller, when tuning the low speed, you are aiming for a nice crisp throttle response, if you run the low speed to lean you will eat through glow plugs very quickly and it can damage your engine. once you start getting close to what you think is the best throttle response, tune in smaller increments, once you get it so as soon as you touch the throttle the engine start revving up and doesn't bog down at all, so as soon as you hit the gas, the truck takes off, once you get to that point do not lean it any further, and for a safe guard i like to richen it by 1/16 of a turn. to test to see if the low-speed needle is set to rich or to lean you need to do the pinch test, all you do is pinch the fuel line, and count how many seconds it takes for the engine to die, when you pinch the fuel line, the engine should idle normally for a second or two, then just before it dies it should rev up a few hundred rpm, then die on the count of 3. if the engine dies in 2 seconds or less, or does not rev up at all, you are to lean and need to richen the low-speed needle, if the engine takes more than 3 or 4 seconds to die, you are too rich and can lean the engine out a bit more. for then engine not start, check to see if the glow plugs good, to do that just take the plug out, connect it to the blue glow wire, hold the glow plug up against the cooling head, insert the starter wand into the truck and press the red button, if the wire in the plug glows it's good, if it doesn’t you need a new plug, if the plugs good it may be because the engine is flooded, so you need to take the glow plug out, pinch the flue line, turn the truck upside down and turn it over with the start wand and see if that helps. once you have done all your tuning you might have to set the idle again, if you do just follow the steps I posted at the top of the page, you should never have to touch the idle screw unless the truck is idling high enough for the clutch to engage, or that low it won’t start.

I need to go with you or what you guys one of these days to go run Nitro

The losi 3.4 carburetor fixes all the issues and wakes up the engine. I love my traxxas jato but traxxas carbs are literal trash. If you want to spend more you can get the O.S. 11k carb it is another direct fit!!!!

Mine was running perfect wheelies and all went to attach wheelie bar and started it and running at crazy idle moving on its own. Messed with settings no matter what just either ran higher or at high setting couldn't get it to idle properly for anything

Lol ohhhhboy Once upon a time I had tuning issues then I realized that carb the low needle will close completely before the pin bottoms out My guess is your carb has been closed to firmly causing bad operations at low idle. Trick for you dude Use a long piece of fuel tubing and blow through the carb with the card upside your ear closing the needles I bet you will see the air closes off shut before the needles ever reach the bottom of the needle seat At the point no air comes through and your blue in the face turn the needles to the stock standard settings BAM don’t forget the idle gap Once I seen the guys video that explained this to me holy heck tuning became a art form now to learn the finest changes and seeking out the most unreal low end power. Good luck man

The one way bering in the ez start is causing alot of drag, The engine is struggling.

❤🎉😮😊

I'm thinking the piston is in backward. Mine was and it would only run with a huge gap. Turned it around and it runs normally .

Lol.