Trucks Tmaxx 2.5 'rebuild'

[Tony]

If that stuff is hard, then someone put epoxy in there to try and seal it. I'm guessing they had tuning issues as well. Seeing that makes me a little pessimistic.

And carbs should only have 1 o-ring that I know of. Just the one to seal it against the block. Make sure to push down and twist really hard to seat it though.

 

[Tony]

That actually reminded me of a carb I worked on a while back. You need to check all passages now inside the carb to verify they are flowing properly. I had one like that which had silicone on it to seal it, and the silicone went into every hole in the carb. Those silver aluminum pieces should both have an O-Ring to seal them. If they don't, they need to.

 

[bigone5500]

Only 1 of the aluminum caps has an oring. The other seemed to have epoxy or thread locker of some sort.

 

[bigone5500]

Oh there's the other one.

 

[Tony]

Hold your phone sideways when taking pictures. Much easier to see lmao.

And I forgot about that lower one.

 

[bigone5500]

See what you think.

 

[bigone5500]

You ain't gonna believe this. I put a traxxas glow plug in and it runs fine.

 

[Tony]

Yup, before I read your last post, I knew it was a glow plug issue. As long as you hold down the button to put power to the glow plug it will run. But as soon as you let go of the starter it will die. I show the same exact thing in my T-Maxx video series.

 

[bigone5500]

Hobby town sold me the OS glow plug knowing I was gonna put it in a truck. WTF??? <---is that legal? $7 for a glow plug that I can't use.

 

[bigone5500]

What are the correct settings for the idle? I seem to recall 1mm gap in the slide.

BTW it runs pretty good. I don't like the clutch in the transmission though. And the reverse is nice but from what I can see, if your RPM is too high it won't shift to either reverse or forward.

 

[Tony]

OS is a good plug. It is what I use in everything that I have nitro. Sometimes they go bad. It's a crap shoot. These engines should take a #8 if I remember correctly.

 

[Tony]

the 1mm gap is a starting point as is the needle settings. Low speed setting is if you pinch your fuel line to cut fuel to the engine, the engine should run for 3 seconds and die. If longer, your low end is too rich. If shorter, your low end is too lean. And every time you make an adjustment to the high speed needle you need to readjust the low speed. Once you get close on the top end and you are only moving it a few hours at a time max, then the low speed should never be touched.

Once you get the low speed set, use the idle adjustment screw to set the idle so that it will not kick the transmission clutch into gear. The spur will still spin, but the truck will not lunge.

 

[bigone5500]

Lunging is what it's doing. I know my settings are out of whack. I'm gonna call today a victory and put it up for now. I ran a couple ounces of fuel through it and putted around the yard till it died. So satisfying.

As for the glow plug, they sold me an OS LC4. Is that wrong?

 

[bigone5500]

TMAMXX 3.3 and 2.5 size difference. The 2.5 is the first iteration short body.

Horizontal photo

 

[Tony]

Any long plug will work, the number is decided on the nitro content of your fuel. The more nitro, the hotter the plug you need. the OS8 is a medium for 20% fuel. The LC4 is also a medium plug, but with a little longer thread. The McCoy MC-59 is another plug to look into that works really well. I may be confusing that #8 with the .15 or .12 I used to run. Been a while lmao.

But to answer your question, that plug is perfect for the tmaxx, you just hit snake eyes on that one plug. But OS makes some of the best plugs on the market. I have had more luck with them than any other plug, next would be McCoy's.

 

[bigone5500]

I'll see if they will exchange it with a Traxxas original part.

 

[Tony]

I wish you luck with that one.

 

[bigone5500]

About to work on the wheel alignment. Oh wait...I don't have a wrench to fit the turnbuckles. Scrap aluminum to the rescue.

 

[Tony]

lol, way better than spending whatever they want for the actual tool. And the wait lol.

 

[bigone5500]

I took the truck outside yesterday and ran half a tank through it. Some things I notice about it are the reverse/forward doesn't work well. The truck got stuck a few times as it would not shift. Maybe the idle is too high? I also noticed that when I would gas it hard it bogged down. Not sure how to resolve that one. Low speed needle? Body off it ran temps around 245F.