2.5 engine problems

[alextrox69]

this is my first post here. i have a nitro rustler but I'm posting in this thread because the regular t-maxx uses the same engine.

i just got my rustler and I'm having problems. this is my 2nd rc car (first was sportmaxx)

i broke it in EXACTLY to the traxxas directions. factory settings come lean for me. 4 turns out is dangerously lean for my engines and I'm confused. i run my rustler a lot richer and it runs great and doesn't show signs of overheating. i know i can get more power out of it, but how can i do that with out it over heating? its very sluggish right now but its fine for me exept its producing nowhere near the power a 2.5 should be making. i run 20% nitro
thanks,
alex

 

[robmob]

You are going to have to lean the HSN a bit to gain more power.

The stock cast aluminum 2.5 cooling head is crap. Upgrade to a machined aluminum like the one Nova RC puts out for better cooling.

 

[alextrox69]

i have a 2.5r colling head on it. i had it on my sportmaxx . if i lean the hsn even 1/8 of a turn it'll overheat...I'm very dissapointed about traxxass engins. is there any way i can get a os .18 tm to fit? I'm talking about the exuasht manifold. ?? thanks

 

[alextrox69]

help? please?

 

[.21Rc10GT]

Have you sealed the carb neck and backplate with silicone to prevent air leaks? How about new fuel tubing?

 

[on_my_can_sp2]

do you have enough air hole in it? the head is crap on my 2.5 it always ran hotter than i like BUT i also got 6 gallons out of it.

 

[alextrox69]

yeah i checked all of that. the tubing is new. i had the car less than a week. i had the same problems with my sportmaxx so i kept driving it off my roof till it broke

[ame="http://www.youtube.com/watch?v=MYACj3RfzRw"]YouTube - t-maxx roof jump[/ame]

 

[Racer 1966]

so i kept driving it off my roof till it broke

I'll bite my tongue on what I think of that statement.

So what is the actual temp when it's overheating? Traxxas motors usually run on the hot side.

 

[alextrox69]

the truck ran about 400 degrees F BUT...it showed no signs of overheating and ran awsome with lots of smoke. i have 3 temp guns btw.

the ruslter right now runs around 270...anything over 290 it shows signs of overheating and cuts out. its running rich to keep the temp down but i know the 2.5 should have more power

theres NO airleaks in both engines

 

[SMaxxin]

My experience with trx engines tells me they all have leaks even if they do not run like they do. Every 2.5 I have owned ran on the hot side until I sealed them, even if you don't have a leak seal the back plate and carb neck ...the temp will drop.

 

[SVORay]

It's been my experience that things cleared up once I installed an OS engine