You T-Maxx guys!

[HondaRacing83]

I'm sure some of you could help me out some here. See I just finished puttin some stuff on my t maxx like new a arms and skids,(a arms are alot more time consuming than you think!) i finally got it back together, and my dad came out( he had t maxxs in his 20's and hes been interested in mine ever since i brought it home) hes like why dont you go run it for a bit, so i had nothing else to do so i did. took FOREVER to get started. i went through like 4 glow plugs, and a quarter of a tank of fuel(new), it was running like ****, i started tuning it abit, then it kept randomly dieing. im like wtf, so after it did that more, i had my dad hold it while i ran it wide open, it died a few times then it started to stay running. then i ran out a fuel, im like ****. that was the last of my fuel, but i have 2 gallons of fuel from 8years ago. ive seen if it seperated before, it didnt. so i figured id try it. it ran for like 1minute then died. then i got it going again and ran 3 tanks of the old fuel after that. i just cant figure out why i cant get it tuned right either, runs like total **** on bottom end but runs like a raped ape on top end. t maxx's should stand up if you whack on them. and ride it out. mine is the classic 1.5. also, middle of the 2nd tank, motor seezed up. i eventually cut it free rolling it over by hand on the metal flywheel, then it siezed again after i started it, then i freed it. then it ran fine again! im not sure whats going on with it. im waiting for it to blow up so i can put a 2.5 motor in it, i hear the 3.3 are a ***** to tune. 2.5's are easier.

[finsteratv]

i liked my stampede with the .15 pro hahaha.

[GAZ-V-21]

The 3.3 isnt to bad fast as hell the tuning does suck though temperature changes and you gotta tune and very hard to get just right i loved the sound and smell of the nitro but hated all the work just to get a little run time so i had to go electric with the brushless motors and lipo batteries these things hang with nitro all day only time you gotta work on your electric is when ya run into something at 65 mph.:devil:

[GAZ-V-21]

Mine and my buddys trucks after independence day trophy race
http://i1095.photobucket.com/albums/i465/GAZVATV/IMAG0013.jpg

[F-16Guy]

If yours is the old style Pro .15 with side exhaust, just stick an O.S. CV-RX .18 rotary carb engine in it. It will bolt right in and once it's tuned, you'll almost never have to touch it again. If you are going to buy a Traxxas engine, the 3.3 is the only thing I would buy, but it will require converting the exhaust and the throttle linkage to the rear exhaust set-up. The TRX 2.5 is a .15 engine just like the Pro 15 and is too small for a T-Maxx. You'll fight overheating issues until it blows up like your Pro 15.

With any of the above engine choices, Traxxas has a bad habbit of over-gearing their vehicles which makes them run hot, so I would also buy a clutch bell with 2 fewer teeth. You'll have to adjust the shift point, but it makes the truck so much more fun to drive and keeps everything cooler.

[HondaRacing83]

I thought about putting a trinity engine in there, yes mine has the side exhaust moutn its the classic

[F-16Guy]

Any good side exhaust, rotary carb engine would work. I wouldn't go any smaller than a .18.

[JForestZ34]

When you try to tune them you don't have to turn the screws far at all. Even a small turn makes a big difference on a motor that small.

If it's not smoking a whole lot and it's dying when your on the throttle most likely it's lean. Richen that baby up just a little.

But look in the book and start at the factory setting on the needles. If your not sure of what your doing you'll never tune it without a starting point. After you get more experience you could set the needles anywhere and tune it within 2mins.

I've had so many nitro's I can tune by sound and how the motor responds and runs. I started off learning and messing up a lot, then I tuned using a temp gun. I still use one from time to time but that is just if I think it's running a little hot.


Do a quick test. Let the truck idle for about 20 secs. While it's idleing see how much smoke is coming out the pipe. After 20 secs hit the throttle and if it speeds up fast and dies it's running too lean. Richen the low speed needle about a 1/4 turn and try again. If you hit the throttle and it sounds like it's stumbling and not revving easy it's too rich. Lean it a 1/4 turn on the low speed.

When these are tuned right they run like a raped ape on roids. But the best part about having them tuned right is when you go out to run the MOST you would have to adjust it would be maybe 1/4 turn in either direction and it would be spot on. The only reason you would have to make fine adjustments would be for outside temp or altitude but the altitude wouldn't change much just mostly temp.

Hope this helps


James

[HondaRacing83]

thanks, i was running it a little to rich, starting to lean it out again. from day 1 though, this thing never had any bottom end. it always starts slow, smokes alot, then it runs incredible on top end. it used to when i stopped it going up a hill, it would sit there and smoke for about a minute and 30 seconds before it actually started to move. what would cause the motor to seize up?

[JForestZ34]

Originally posted by HondaRacing83
thanks, i was running it a little to rich, starting to lean it out again. from day 1 though, this thing never had any bottom end. it always starts slow, smokes alot, then it runs incredible on top end. it used to when i stopped it going up a hill, it would sit there and smoke for about a minute and 30 seconds before it actually started to move. what would cause the motor to seize up?


No it wouldn't cause it to seize up. If it has good top end and crappy low end the low end isn't adjust correctly. If you hit the throttle and it takes a while for the motor to rev up like it stumbling it running to rich. Lean the low end needle only and test again. Keep doing it until when you hit the throttle you have instant acceleration. Then I usually richen it up 1/8th of a turn just to be safe. Better to be a little rich than too lean.

You do know there are two needles on the carb right? Low speed and high speed. You have to adjust the low speed before the high speed. So if the low speed you make a drastic change it will effect the high end also.

Doesn't sound like your far from where you should be.


James

[HondaRacing83]

Originally posted by JForestZ34
No it wouldn't cause it to seize up. If it has good top end and crappy low end the low end isn't adjust correctly. If you hit the throttle and it takes a while for the motor to rev up like it stumbling it running to rich. Lean the low end needle only and test again. Keep doing it until when you hit the throttle you have instant acceleration. Then I usually richen it up 1/8th of a turn just to be safe. Better to be a little rich than too lean.

You do know there are two needles on the carb right? Low speed and high speed. You have to adjust the low speed before the high speed. So if the low speed you make a drastic change it will effect the high end also.

Doesn't sound like your far from where you should be.


James im going out to mess with it now, thanks

[HondaRacing83]

Originally posted by HondaRacing83
im going out to mess with it now, thanks well, i just ran it 2 turns out. ran better than it ever did, but ran really hot. its the best it ever ran, but, its still not right. should run similar to this, http://www.youtube.com/watch?v=_lvF5r5IKuQ
its still a bit slow taking off. what should i adjust next? my dad said to run it 2 1/4 turns out so its not to lean. should i adjust idle screw? or low speed?

[JForestZ34]

Originally posted by HondaRacing83
well, i just ran it 2 turns out. ran better than it ever did, but ran really hot. its the best it ever ran, but, its still not right. should run similar to this, http://www.youtube.com/watch?v=_lvF5r5IKuQ
its still a bit slow taking off. what should i adjust next? my dad said to run it 2 1/4 turns out so its not to lean. should i adjust idle screw? or low speed?

The more turns out the leaner it gets. The head temp really shouldn't get above 220-240 degrees. Do a simple test. Rip it around a little bit and bring it right back to you and quickly pit spit on your finger and wipe it on the top of the head of the motor. If it boils of within 1-2 secs it's running too hot. If it takes 5 seconds or more that is about right.

Sounds like your getting closer. Just make sure there is a good amount of smoke coming out the exhaust. If you don't see smoke when your running it stop it cause its way to lean.


James

[JForestZ34]

Originally posted by HondaRacing83
well, i just ran it 2 turns out. ran better than it ever did, but ran really hot. its the best it ever ran, but, its still not right. should run similar to this, http://www.youtube.com/watch?v=_lvF5r5IKuQ
its still a bit slow taking off. what should i adjust next? my dad said to run it 2 1/4 turns out so its not to lean. should i adjust idle screw? or low speed?


Just make sure you let yours warm up a little bit before you rip on it like in that video. You'll seize the motor up easily like that.

You only have to adjust the idle screw if from tuning the motor it causes the idle toraise or lower. Usually when that's set you don't haveto adjust it much


James

[muddy400EX]

just gotta get better at tuning. you can tune it completely from sound once you know what to listen for

if its bogging and smoking like crazy like u say urs is doing, then it is to rich.

if it revs really high when you let off then its to lean

like this
<iframe width="560" height="345" src="http://www.youtube.com/embed/Me-mmbEKQ5c" frameborder="0" allowfullscreen></iframe>

hear how it sounds like its starving for gas when he gets on it? the top end screw is to lean and its not getting enough gas

and its not a 1.5. its the old pro .15

the pro .15 and 2.5 is the same size motor, the 2.5 is just a "race motor" so they call it

.15 ci = 2.5 cc

and for motor dont even mess with the new 2.5. go straight for 3.3 or bigger

get this bad boy, im sure you would need some other parts to make it fit, but it would be a beast
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKHF0&P=Z

[HondaRacing83]

i was asking my dad about tuning, he said to never go under 2 turns out. is there a certain number i shouldnt go under on the low speed?

[JForestZ34]

Originally posted by HondaRacing83
i was asking my dad about tuning, he said to never go under 2 turns out. is there a certain number i shouldnt go under on the low speed?


That depends on a lot of things like fuel, oil content, air temp, stuff like that. Your getting closer



James

[F-16Guy]

I always dial in the wide open throttle (high speed needle) first. Richen it (ccw) until it starts to not "clean out" on the top end during full throttle runs and then lean (cw) it back down a little at a time until you get a nice, clean wide open pass. Once the high speed needle is set, adjust the low speed needle. I always start rich and then lean it until the rich stumble/hesitation is gone. At that point, adjust your idle if you need to. It's going to be tough with a Traxxas engine. Make sure it doesn't overheat while tuning. If it does, allow it to cool and then try again. Also, I really suggest going a couple teeth smaller on the clutch bell. It really won't hurt the top speed, and it will give you better bottom end and keep things cooler.