The Beer Vs. TRX Engines Saga Continues….

[Beer_Goggles_RC]

To preface I’ve ran multiple OS, Alpha, Kyosho, and even Force engines without any problems..

I’ve had 4 or 5 TRX engines 2.5 & 3.3 (all pre owned) and not a single one of them could I ever get running right. Mostly high idle issues. Engine temps and performance are ok, but idle high enough for the car to move with no throttle input. If I were to take an hour or two off then the idle will come down, but eventually bog and die. No matter the idle gap. And it bothers the hell out of me.

I hear traxxas carbs are pretty bad. Seems to me like an air leak issue on the carb.

Purchased the OS11k and installed on my 2.5 rustler in hopes of smooth sailing..

I can finally get the idle down to a typical idle without bogging and dying.

Now my problem is the high speed.. Can’t get a good tune on the high speed without it now flooding the engine and killing it after full throttle.

When I get the high speed to the lowest hour where it won’t kill the engine after a pull, I’m getting 300+ temps at the plug.

I’ve tried .3 - .8 mm idle gaps w/ fat and lean LSN thinking maybe the gap is wrong and can’t keep up with the fuel delivery. Nope.

What do y’all think? I think I should never buy a traxxas nitro again. Bad engines? Bad luck? Stupid?

Idc I’m pretty much over it at this point.

Running Sidewinder 30% Race Blend btw..

 

[Tunedfrog]

I'm not a nitro guy so I couldn't suggest anything. Good luck though.

 

[Chubaka]

I've heard excellent reviews about the 11k and 11r carbs. Ones for tmsxx style the other revo style setups. Also heard great about the losi 3.4 carbs but those are long gone.

I've had good luck with my 3.3 when I used it. The traxxas .15 were solid stleast back in the day.

I think hpi was one if the nicest motors i had and tuned. It was a t-15 in the Nitro RS43 evo.

 

[Beer_Goggles_RC]

I've heard excellent reviews about the 11k and 11r carbs. Ones for tmsxx style the other revo style setups. Also heard great about the losi 3.4 carbs but those are long gone.

I've had good luck with my 3.3 when I used it. The traxxas .15 were solid stleast back in the day.

I think hpi was one if the nicest motors i had and tuned. It was a t-15 in the Nitro RS43 evo.

Yeah man I thought the 11k was gonna be the key. I’m ready to give up on the traxxas thing lol

 

[tudordewolf]

Have you tried leaning out the low-speed needle? It sounds like the low-speed is a little too rich, and the high-speed a little too lean, if it's running hot/lean at WOT and bogging out at idle. I had the classic "high idle, bad tune" issues, swapped in an 11k and it sang.

 

[Beer_Goggles_RC]

Have you tried leaning out the low-speed needle? It sounds like the low-speed is a little too rich, and the high-speed a little too lean, if it's running hot/lean at WOT and bogging out at idle. I had the classic "high idle, bad tune" issues, swapped in an 11k and it sang.

It's not bogging at idle, only after it goes from WOT and straight back to idle. It’ll idle like a dream with good snappy acceleration until I put is on the ground and give it the beans. Like there's too much fuel delivery. Essentially a severe reverse 2 stage idle.

Runs fine on the stand though.

I did notice that even when 80% full if the fuel tank leans forward (away from the fuel pickup) it’ll go really lean and if it leans back it’ll go super fat.

Wondering if the acceleration is pushing forcing fuel to the back of the tank and making it go fat? Idk

I’ve got a new tank on order and I’m gonna redo the fuel lines to see if that helps.

 

[Littlemotor]

If you’re confident in your tuning abilities, and properly diagnosing the symptoms, then I’d begin looking away from the engine. As you mentioned; the lines, tank, and tank seal.. If all that checks out, and is good, then move on to clutch, and clutch bell bearings..

That tank definitely has an issue though-with what you described as far as simply leaning the vehicle fore, & aft, and it changing rpm.. That’s a ginormous red flag. I’d be inspecting the pick-up, and line inside the tank itself. Fairly common to develop a kink, a hole, or just straight up not be in the right spot.. But it also could be that the tank itself is losing pressure when the fuel uncovers a particular spot in the tank.

There is a multitude of things that would cause this-but I’d start at the tank for sure before moving forward with anything else.

 

[fstnd]

Well I'm glad a new guy to the hobby bought a nitro savage, as I also recommended a traxxas

 

[alfredwong2003]

Check the friction pegs if they are warned. Then check your clutch.

 

[CertifiedMike]

Read OLD nitro threads... I remember ppl having tank issues years ago but I don't remember which ones.
I think it was ppl replacing 2.5 with 3.3 but its been a LONG time!
No chance your exhaust is plugging up with fuel?
Not returning to the tank?
Is the fuel tank cap seal good?

 

[Beer_Goggles_RC]

I swapped out the tank but then temps plummeted and it's been sitting since. Exhaust and everything look good. If this doesn't work I'll check for air leaks. If that doesn't work I'll throw it in the damn trash and never buy a Traxxas again

 

[easy rider]

People do horrible things to a nitro motor. Traxxas is the most popular brand for new comers. There’s far more of those bought by first timers then any other. They don’t know how to tune. They get the dang carb so fouled up by constantly adjusting on it. Etc….


Buy a new motor. You won’t have any problems with it. That carb you bought will make it the easiest starting, most consistent motor you own.

 

[Littlemotor]

People do horrible things to a nitro motor. Traxxas is the most popular brand for new comers. There’s far more of those bought by first timers then any other. They don’t know how to tune. They get the dang carb so fouled up by constantly adjusting on it. Etc….


Buy a new motor. You won’t have any problems with it. That carb you bought will make it the easiest starting, most consistent motor you own.

Not everyone wants to “fix” their issue(s) by throwing their check book at it… LEARNING how to properly maintain, and diagnose problems comes with running a nitro engine. I’ve seen people have issues with brand new engines right out of the box more times than I can count. Literally everything mentioned in this thread above will get him sorted out. “Just buy a new engine, and you won’t have any problems with it” is the only actual bad advice in the entire thread. That leaves literally ALL of the other possible, and PROBABLE issues untouched/not looked at… A new engine does not address a leaking tank, bad lid o-ring, kinked or punctured fuel line, broken clutch spring, dragging clutch shoe, worn, and galled CB, smoked CB bearings, linkage issues, and the list goes on goes on… Also another reason I don’t run an external fuel filter on my expensive nitro engines; its yet another possible failure point, and has the potential to do more harm than good when there’s a brass clunker in the tank..

Learning, trial & error, patience, and EXPERIENCE are all a huge part of nitro RC.. -not just “buy a new one, and your problems will be solved”…

 

[easy rider]

Not everyone wants to “fix” their issue(s) by throwing their check book at it… LEARNING how to properly maintain, and diagnose problems comes with running a nitro engine. I’ve seen people have issues with brand new engines right out of the box more times than I can count. Literally everything mentioned in this thread above will get him sorted out. “Just buy a new engine, and you won’t have any problems with it” is the only actual bad advice in the entire thread. That leaves literally ALL of the other possible, and PROBABLE issues untouched/not looked at… A new engine does not address a leaking tank, bad lid o-ring, kinked or punctured fuel line, broken clutch spring, dragging clutch shoe, worn, and galled CB, smoked CB bearings, linkage issues, and the list goes on goes on… Also another reason I don’t run an external fuel filter on my expensive nitro engines; its yet another possible failure point, and has the potential to do more harm than good when there’s a brass clunker in the tank..

Learning, trial & error, patience, and EXPERIENCE are all a huge part of nitro RC.. -not just “buy a new one, and your problems will be solved”…

My man. I could type a page of reply explaining my response wasn’t meant the way you are implying. I’m not going to do that.

To the OP. I didn’t read the whole thread. Just your first couple and the one where you said the 2.5 wasn’t acting right still. And, I replied the way I did because you have a stable of used parts to support a new motor purchase. Those parts bought for a complete rebuild cost more than a complete new motor. It’s a lifetime of parts.

That’s why I said it. I never meant it wasn’t worth fooling with. No disrespect meant.

 

[Littlemotor]

My man. I could type a page of reply explaining my response wasn’t meant the way you are implying. I’m not going to do that.

To the OP. I didn’t read the whole thread. Just your first couple and the one where you said the 2.5 wasn’t acting right still. And, I replied the way I did because you have a stable of used parts to support a new motor purchase. Those parts bought for a complete rebuild cost more than a complete new motor. It’s a lifetime of parts.

That’s why I said it. I never meant it wasn’t worth fooling with. No disrespect meant.

“My man”, you literally instructed the guy to buy a new motor, and he won’t have those problems. There is literally no other way to read it. How you “implied” it, is exactly how you relayed it. “I didn’t read the whole thread”…. Then how can you provide any sound reasoning, diagnosing, or help? Backpedal all you want, or don’t own what you said-but please refrain in the future from dispensing utterly terrible advice.

 

[easy rider]

“My man”, you literally instructed the guy to buy a new motor, and he won’t have those problems. There is literally no other way to read it. How you “implied” it, is exactly how you relayed it. “I didn’t read the whole thread”…. Then how can you provide any sound reasoning, diagnosing, or help? Backpedal all you want, or don’t own what you said-but please refrain in the future from dispensing utterly terrible advice.

I thought I was helping him. I made that clear.