New Maxx New Nitro Owner with ISSUES

[c0mf0rt]

First time owning a nitro truck. I've had the T-Maxx 3.3 for about a week and I've already blown a piston. Here's the situation.

It was brand new. Did the full break in period. The carb is set about 4 1/4 turns out on the hsn. I had what I thought was plenty of smoke. When I finally had it all dialed in; it would not cough or die out. Then today while bashing around the yard it just quit.

I pulled it up and had a tiny bit of smoke coming out around the plug/cylinder cooler. The EZ start was indicating a motor error. Pulled out the plug etc. and now I have a hole in the piston.

Any ideas? Do you think Traxxas will help out with free warranty parts?

Even if they do help I'm worried I'll burn another one. How else can I tell if I'm running lean/rich if the engine is running/idling fine and I have plenty of smoke?

TIA

...one other thing.... I'm not totally sure I ever heard it shift into second.

 

[Racer 1966]

I can't say if Traxxas will help or not but one thing you need to help verify your tuning is a temp gun. It may have helped save your engine depending on what really happened to it.

 

[c0mf0rt]

What about the on board temp sensor from Traxxas? Would that work as well as a gun?

 

[olds97_lss]

They work ok, but a gun is more definite. Usually you measure with a gun to figure out where to put the thermistor from the onboard temp gauge. Or at the very least to know how far off it is.

 

[c0mf0rt]

Gotcha, thanks. So no opinions on whether or not Traxxas will backup the motor?

 

[Mineverun09]

only traxxas knows the answer to that question..

 

[brokeitagain]

Not sure personally but id think they would givin the conditions. A couple things id mention tho from my experience with nitro.
1. Definitly get a temp gun. You can get them at your lhs, or places like harbor freight have them for like 10 bucks. Best money you'll ever spend for tuning help.
2. If it wasn't shiftin that typically means too rich, and you can definitly tell when they shift. It makes a clear change in engine speed and sound and you can hear a distinct stutter when it shifts. (Its quick but sounds kinda like f1 cars shiftin)
3. If it was smokin around the coolin head it was definitly too hot. One of the issues these motors have is they need to be sealed even when new on some of them. Air tight is right otherwise it'll always run lean. Do a search and you'll easily find links on how to seal the motor.
Good luck with it and hopefully traxxas will help ya out and square iit away. Just out of curiosity tho did you run it hard right after startin it, or did you let it warm up before gettin on it?

 

[c0mf0rt]

After the break in I didn't really let it warm up.... I got it started and would run it around the yard... probably part of the problem huh?

 

[brokeitagain]

Yea from what I've read on here, if you don't let them warm up, the piston and sleeve don't expand enough causing the engine to be really tight and put a lot of extra strain on the con rod. That's prolly what did it, I just wouldn't mention it to traxxas lol.

 

[c0mf0rt]

lol... .I didn't.... talked with them today and its in the mail.... they said they'll tell me after they take a look at it.......fingers crossed.

 

[brokeitagain]

Good luck with it man, let us know what happens. I'm just curious to see how it goes since I haven't messed with traxxas cust service yet.

 

[c0mf0rt]

Thanks.... I have read a few other things on here that said people got their motors replaced so again... fingers crossed.

 

[Metalhead Matt]

Seal the new engine before you install it. Read the tuning tips and tricks at the top of the nitro forum. It explains sealing in detail.

 

[c0mf0rt]

Update... Traxxas is hooking me up with a new engine! Sooooo I will take my time breaking this new one in. I've picked up a temp gun. I'm a little afraid to seal in case I have any more issues. I don't want Traxxas blaming my seal job on any issues. I think I'll hold off sealing it for a month or so to make sure everything is kosher.

So any tips on what the temps should be? Do I let it warm up before each break in tank or get right to it? Any real drawback to running it rich? I REALLY don't want to cook another one by running it lean.

 

[Mineverun09]

DONT TOUCH THE SETTINGS FOR ANYTHING WHILE YOU BREAK IT IN.
they're set from the factory for breaking in. go to the traxxas website and read on how to break in an engine, or go here- https://www.rcnitrotalk.com/forum/showthread.php?t=60832
and its post number 5 by rolex. read it, do everything exactly as it says.

and curiously did you just send in the first motor? did they know when you bought it?

 

[c0mf0rt]

I called.... spoke with someone....they said to send it, an explanation, and a copy of the receipt. That was about it.

 

[olds97_lss]

Personally... I never trust the factory. I always adjust it according to specs before firing it up. I've received two brand new in box engines that were totally wrong. One had the HSN screwed all the way in, the other had the LSN all the way in and the HSN 2 turns out too far.

Adjust it according to the manual, then fire it up and follow the recommended break-in process.

It's also a good idea to check the head bolts, back plate bolts and carb cinch bolt for tightness as well. I've received a few that were loose (carbs are usually loose due to the end user needing to adjust it anyway).

 

[c0mf0rt]

So temp ranges I should be looking for during and after break in?

 

[Mineverun09]

dude READ some stuff. this forum is filled with great information. that link i posted has everything you could ever need to know about an engine, sealing, and break in process.

 

[c0mf0rt]

lol... thanks....