S-maxx problem. (Yet again).

[trainguy]

My S-maxx won't start again.

I had started it fine, then I go and do some highspeed runs on the street out front and it makes an exploding sound (almost like a backfire) and quits.

Now it won't start again.

The motor temp wasn't even 120 degrees yet.

The ez-start lights come on fine. Then it wont do anything, not even a sound.

Busted head gasket?

Any help?

Thanks,
Trainguy.

 

[SteelCityNitro]

I'm almost wondering if you busted the piston rod.. take it apart and see what you find

 

[Macguyver]

I'm almost wondering if you busted the piston rod.. take it apart and see what you find

+1 on that ...if you did high speed runs at less than 120deg ...chances are the engine components didnt have time to expand and the piston was still to tight in the sleeve ...so your high speed runs may have made the engine work harder than it should , and something broke inside

always bring it up to normal operating temps before you try to do high speed passes .

hope that makes sense ...

 

[cwal1774]

Yep I almost bet the connecting rod is split right down the center.

 

[trainguy]

My LHS said it might be a broken connecting rod or a broken crankshaft over the phone.

I'll take it over there Saturday. I'm still new to these R/Cs.

Never taken a motor apart, not even added anything to a real car so I don't know what I'm doing.

 

[SteelCityNitro]

My LHS said it might be a broken connecting rod or a broken crankshaft over the phone.

I'll take it over there Saturday. I'm still new to these R/Cs.

Never taken a motor apart, not even added anything to a real car so I don't know what I'm doing.

Well if you are feeling curious, there is a thread on here somewhere explaining how to seal an engine. All nitro engines are typically the same. You can use that as a guide on how to take it apart and re-assemble it... or you can look on www.traxxas.com.. just look under the knowledge base and it might help you as well. There is no better time than now to learn how to do it

 

[Macguyver]

here is the link to the thread ...these small engines are pretty easy to work on

https://www.rcnitrotalk.com/forum/showthread.php?t=60832

 

[SteelCityNitro]

here is the link to the thread ...these small engines are pretty easy to work on

https://www.rcnitrotalk.com/forum/showthread.php?t=60832

That's the one! I was just too lazy to search for it

 

[rak12]

Same exact thing happened to me when I was about half gallon into my 3.3 maxx. Same sounds and symptoms and yes it was my con rod! split right down the middle with the bottom of piston chipped all around. I sent it to Traxxas and they rebuilt it under warranty ( I think they had pity on me which I freely accepted) but Traxxas always has thier lifetime engine replacement plan. I'm assuming your rig still has a traxxas mill. this route is usually cheaper and probably more reliable tahn having a LHS fix it when you consider the parts and labor.

 

[trainguy]

I've been looking into getting parts to repair it. Looks almost as expensive as buying a new motor. It was the connecting rod and crankshaft.

I'm thinking about replacing the motor with a new one.

I'm looking for one under $250 US. I would like it to have higher preformance than the trx 3.3 if possible.

Any ideas?

 

[frickenjoey]

Picco .26 Maxx. You will need the mount for it but even with that you are under 250 and it will be darn near double the power of the 3.3trx.
Picco Maxx .26 Engine & Picco Red Dot .26
Engine Mount