imnew4321

Ok, I have had my tmaxx 2.5 for about three years(I think) and it now doesnt want to stay running or at an idle speed. is the 2.5r a better motor or is this one better [link=http://www.traxxas.com/products/nitro/trx15pro/trx_trx15pro.htm]here[/link] or would a new exhaust be good or is the 3.3 better running than the 2.5 thanks

maxmania214

you could try and replace the piston and sleve this is the most common and also an air leak the front bearing is prone for that

but the 2.5 is a ***** to tune any way thats y i upgraded to a 3.3 lol

3.3 all the way baby its easier to tune and is a hell of a lot more responsive!!

DaveG55

You need to decide what you want when you're done with the upgrade. Do you still want to use the ez-start? Do you want the same power/performance or more? Do you want a real easy swap out or are you willing to make some modifacations - other than the motor?
Basically that Pro.15 you listed is an even exchange. Every thing will work, it's an easy swap and power/performance will be about the same.
Either the 2.5/2.5r or the 3.3 will bolt on but you'll need andn addational upgrade kit (about $25) and an ez-start system that is compatable with those engines. Either will have considerably more power than the Pro.15 with the 3.3 having more than the 2.5.
Or there's the OS.18 CV-RX(s). It's a direct drop in to the Pro.15 except you'll have to use the included pullstart since the ez-start will not work with that engine. This engine will give you more power than the 2.5 but not quite equal to the 3.3 - close but not quite.
There's also the OS.18TM which is on a par with the 3.3 power wise but much more reliable and easier to tune. It will need the same modifacations as the 2.5 or 3.3 to install and it too will need a 2.5/3.3 compatable ez-start.
Any of those engines will work w/o having to make many - if any - driveline upgrades.
Then there is the Picco .26 Maxx. Way more power, and lots of mods to make it fit and probably future driveline upgrades too.
And finally, if you really want to have a fast, powerful truck there are tos of Big Block engines that can be made to fit.

imnew4321

Well i already have the stock motor in my tmaxx so I could just go out and buy a 3.3 and just drop it in right? and if I bought the os .18tm what whould I have to do take out the motor mount? thanks guys, How do you take the piston out of the cylinder of a 2.5 thanks again

lanerbrainer205

heres my input... ok if you are looking for power the fastest drop-in is the 3.3, however the O.S. 18 is a REALLY well rounded reliable engine. the only difference between the trx2.5 and the trx2.5r is the cooling head.... if i were you i would get the 3.3 because im a power freak also i think the ofna .26 is drop in with just a engine mount thats bout 20 dollars and it would be about 220 total from TH i changed my mind i would get the .26 heh heh heh [>:]

sloshedmr_bones

you want a good upgrade go with an os.18 cvrx(s) its $110 so the price is good its easy to tune and after about half a gallon you can pull wheelies or just haul @$$. Its worth it. I like the 3.3 but i dont like traxxas engines cuz they are the hardest thing to tune. The os offers power, good price, and easy tuning. As long as you take care of the engine, keep your piston at bottom dead center when your done running you wont have a problem. Whatever you do dont just take the piston and sleeve out. Its a waste of money. I did that with 2 engines and i wish i had never done it. The choice is ultimately yours my friend and I leave it in your hands.

imnew4321

ok thanks