Trucks T-MAXX questions

[puter]

Hi. Noob first post. I picked up a used T-MAXX. The engine has "2.5" on the side of the block. How do I know if it s a regular 2.5 or a 2.5R?

Also, it was not in the best of shape. I watched Tony's videos about teardown, rebuilding, and buildup. A couple of questions...

1) Tony mentions to place the shocks into the middle position. There are three positions on the top of the shock tower, but there are four positions on the arms. Which is middle for the arms? Would it be the second one inboard, or outboard? Also, he said that he would set the gear mesh when he installed the engine, but there was no more on this part. Can anyone describe adjusting the mesh? Would it be engaged, yet not binding? I also noticed on the carb (the part in the vid where he puts on the fuel lines) that his fuel inlet on the carb is pointed a different direction than mine. Can I just move it?

I had to buy a pair of shocks. I found that one was of a different type of body and was leaking. Found some ultra shocks (grey body) from Tower Hobbies. Is that a good place for parts?

I will probably have more questions when I get close to firin' this thing up.

 

[Tony]

Hey puter! If all it says is 2.5, then it's more than likely NOT the R.

As for the shocks, If you are doing a lot of jumping, then put them in the inner center hole. If you are doing a lot of turning, then put them in the outer center hole. Hope this makes sense. If you are turning a lot, you want your shocks to lean over more. If you are jumping a lot, you want your shocks to stand up more. I have plans on making some videos on this, just need to get a vehicle first.

And sorry, I don't know anything about tower's shocks.

As for the gear mesh, you want the tightest mesh you can get but still have play between the spur gear and the clutch gear. You do not want a tight mesh meaning you must have some play in it. About 1/10th of a mm. To adjust this, you will use the 4 bolts that bolt the engine mount to the chassis. Loosen them up, slide the engine over and tighten two of them down. Check your mesh. If it's too tight, scoot the engine over a bit and do it again.

 

[puter]

Hi Tony!

Thanks for the reply! Never had a real live movie star answer me.

So, to repeat, there are four holes on the arms for the shocks. Evidently this T-MAXX was setup for jumps. I understand that with the four holes, setting at the second hole closest to the wheel/tire is for curves, the second hole closest to differential is more for jumps. Got it. I am setting for curves since I am new at this. Figure I'll try flat ground for a while first.

FYI, it appears that I have "Traxxas Ultra Shocks" according to what I ordered. At least this is what the ones look like on the truck right now.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMHY4

I did not remove the engine mount. According to what you are saying, the gear mesh is good. Thanks!

My last stupid question for today - Both of the trucks I picked up (this one and a Traxxas Slayer 3.3 for $150) have the EZ-Start system. It does not look like the glow plug wire has ever been snipped from teh harness. What I mean is that it does not look as if it has been connected to the glow plug. Do I need to connect the wire to start the engine? I know, really stupid question. I'm a noob.

 

[Tony]

Movie star? Not me lmao. I'm just a regular rednek in Oklahoma lol.

The blue wire will need to be connected to the pin on the glow plug and the black wire secured to teh engine mount bolt. This way, you power the glow plug when you hit that button. The last owner was using a Glow Igniter to start it if it was not plugged in. Gets the plug a little hotter and is easier to start with a seperate glow igniter.

 

[puter]

The blue wire will need to be connected to the pin on the glow plug and the black wire secured to teh engine mount bolt.

I'm sure that you meant to say the yellow wire to the engine mount. That is the one that has the round connector while the black wire goes to the EZ-Start motor. As I understand it, red is positive, black is negative, and yellow is ground.

Darn, two things I did not get from previous owner (he passed away 1.5 years ago and I picked all of his stuff up from his widow). Also did not get a charger, but my Thunder ac680 came in today and is charging my batteries. Woot!

Thanks again, Tony.
I'm sure I will have lots more questions.
For now, the Slayer is ready to start once the EZ-Start battery is charged. I feel like a kid again!

 

[Tony]

Let us know how it goes.

 

[puter]

Slayer did great on the first tank of gas. Had a blast and it ran fantastic! But once I opened another can, it sputtered, wouldn't idle right, and I ended up stripping the spur gear. Oops. Guess I will try fresh gas.

T-MAXX, it started for a moment, then died. Won't start. Different can of gas.

Already tore the Slayer down to replace the gear. I don't think someone had the mesh right. Back to the drawing board.

 

[Tony]

If you are changing brands and/or %'age of nitro, you will need to retune your engine. You should stick with the same fuel at all times. Blue Thunder Sport is great for back yard bashing. If you want max power, get some O'donnell 30%. It's what I used when I raced and man, that stuff made some power. But the more power you make, the less life your engine will have.

 

[puter]

I picked up these two trucks with 3.5 quarts of fuel and a gallon of fuel (all 20%). I think it's the age of the fuel. I bought all of this from a widow who lost her husband 1.5 years ago, so it's been sitting since. When I went from the first tank to the next, it was the same brand and type, just another can. I got all listed plus another set of tires/wheels for the T-MAXX, starters, controllers, bodies, plus a tacklebox full of parts and tools for $150. So I figure I can spend a little for fresh fuel to see what happens.

Thanks for the reply. I know that the Slayer was running awesome on that first tank. So I will try fresh fuel and may have to tune from there.

 

[Tony]

One thing you need to invest in is a temp gauge. It's possible that you got the engine way too hot and killed the piston and sleeve.

And one thing to remember about nitro fuel, it's mostly Methanol, or Alcohol. Alcohol absorbs water like a sponge. this is why it's imperative that you run after run oil after you are doing driving. It keeps the fuel from soaking up water from the air and rusting every part in the engine.

Set your high speed needle to 1.75 turns out from seated (when I say seated, I mean LIGHTLY turn it in until it stops. If you drive that thing into the seat, you will destroy the needle and seal) and put the low speed needle to flush with the carb body. This is the factory settings.

When this engine is running, there should be quite a bit of smoke coming out of the pipe. If there is not, then you are WAY to lean.

 

[puter]

Thanks for that! I have been rebuilding carbs (Holleys, Quadrajets, Edelbrocks, etc) for almost 40 years so I know what you mean by lightly seat. I was playing in dirt so I am not positive on how much smoke I was getting. When I first tried it on pavement it looked good. And after trying that second tank of gas I seemed to have gotten some fuel spitting out the exhaust since I have a mess back there.

I saw the vids from Traxxas. I sprayed in the carb and head for 1-second bursts with WD-40, then cranked the engine for ten seconds. Did that three times. That was one of the first things I got the other day at the Hobby store was After-Run oil (along with a fuel bottle). I have already done the after maintenance. I checked teh compression and it is still strong. So I hope that I have not done any internal damage to piston/sleeve.

I've been reading up and watching youtube vids on tuning. Will definitely have to spend some time with that. For now, I have my list of things to get at the hobby store.

 

[puter]

Set your high speed needle to 1.75 turns out from seated

Dangit. That was part of the problem. I did this. I found that is for the LSN, not the HSN.
I needed to go 4 turns with the HSN.

http://traxxas.com/support/Carburetor-Care

I'm rebuilding the carb now because I found that when it would start it was like the throttle was wide open, then it would quit. I couldn't get it to start unless I placed a few drops into the carb itself. I am thinking that since this has sat for a while that there is an issue with the carb. We will see. Never rebuilt one of these little guys.

 

[Tony]

Ah crap, that was my bad bro. 1.75 is where i set my Align 600 Nitro OS 55HZ at. Man, I should have looked that up. My apologies.

 

[breeze400]

Make sure you soak that carb in some carb cleaner overnight then. Use light air pressure to clean out the passages. Probubly have some dryer out fuel blocking the passages.

 

[puter]

Aw, no problem Tony. It helped me to learn.

I did take the carb apart and clean it well. Did not have another seal kit, but they looked fine. Used a guide on Traxxas' website. Set the HSN and LSN to factory settings and the thing fired up! Idled high. The HSN was dead on. The LSN was a bit lean. But the darn thing ran great! Ran three tanks through it yesterday. Then did the tuning I mentioned today. Busted a shock, but it was the bad one anyway. I have three other old ones until the new ones get here. I even adjusted the electronics a little more (throttle/brake and steering).

I also made an order for a NiMH Glow Plug Igniter, 3 spur gears for the Slayer (since I probably won't get it right the first time), and an antenna for the T-MAXX controller (busted). That's it!

All told I have about $250 into this so far.
Not bad for the two trucks and everything that I have.
Now for practice and tons of fun!

 

[Tony]

Good deal that it fired up. Remember you have an idle screw that you can use to adjust the idle. also, the low speed needle will play with the idle speeds a bit as well. Now, we just need video.