Post all of your thoughts about the 2.5 engines here.


Me and 3 other people have bought a traxxas vehicle and all of the engined are gone. Two 2.5's are gone and two 2.5R's are gone. all of them have the same problem, piston is cracked. Anyone have a suggestion on what engine to buy for under $200?

Pick an OS and go from there. I think OS makes some of the most reliable engines known to man.

you could do the life time trade in thing for traxxas but thats like trading a rotton apple for a rotton bananna!!!!

i have a 2.5r and have no problem .and i have a 2.5 both nice motor never had a problem... did you broken them in right? what the temp it was runing?

Or you could pay the $134 or so dollars and trade up to a 3.3 which is a much better motor

you guys all suck Traxxas for LIFE

yea im traxxas for life.. you cant say that there no other brand that makes after market parts for... and its SO much easyer to get parts for....

the truck is cool and yes we did everything as per the video no exceptions. new airfilters every hour ran exactly like the video said. used temp guns the works. these engines were not abused at all. im his brother/pitman and we both run rossi engines in our 8th scale onroad cars and never have the kind of tuning difficulties out of them. the traxxas engines are cheap and put out lots of power but weve had the rossis through 6-7 gallons and they are just like new. the traxxas is a cheap motor that is meant to exchange regularly. how else could they make a new engine for 100 dollars and make money

I have run quite a few OS and REX engines as well as Trx. I have had no problems with my 2.5R or my 3.3. I put 13.5 gallons through one of my 2.5r's before it gave up but it ran flawlessly the whole time. I always run the Odonnels 20% fuel with grape additive, and traxxas 3232 plugs. I place the piston at bottom dead center after EVERY run and use hobbico after run oil at the end of the day. I would highly recomend TRX engines to anyone. The only engine that I have had problems with were TWO Trinity Sirio .18's. I actually gave them the benifit of the doubt and bought a second one because I thought I got a lemon.I could not get either one to stay in tune. I also would recoment the OS .18 TM or TZ as long as you install the RD rod spacer otherwise they will not last more than a gallon. I run the same fuel and perform the same after run routine but use OS P3 plugs. I know that every now and then there are bad engines but most of the time it is the operator.

The engines are fine if you take care of them. are you running a T-MAXX? If so, the problems you are having directly related to the gas tank. It's either the height of the tank or the fuel pick up that makes tuning impossible. If you run on a track you can see lap after lap the engine will steadily go lean. Put an OFNA tank on it.

There is nothing wrong with the trx 2.5 or 2.5r, I have owned several of them and now own a 3.3. None of them have suffered premature failure, 2 of them have seen more than 6 gallons of nothing but hard bashing. I will admit that they tune different than most other engines but run long and strong.