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