Ok. I have decided to get a Ofna MBX Pro. The only problem is I want a different engine, I plan to sell the stock one.

I've been looking and reading other posts and I hear the O.S. .21 RG-X (P) is a good engine.

I just need to know how well it will fit because the exaust and pipe or what ever connector the the engine combined with the engine costs, this thing is going to cost me $170+shipping.

So please tell me if you think this will fit nicely, and what I need to do to make it fit. Anyone with experience with this please help!

Also, I was wondering if this engine will last me long, and the reliablity of it. I have heard that the stock engine on mbx (or any rtr's) are suck. Some guys said it gets really hot and you have to run it way rich.

I havent tried it, but I believe the Force .26 that comes with the Ultra MBX Pro is a decent engine. OFNA use it in a wide variety of viechles, including the Titan monster truck series and the 9.5 series. Anyone else got a comment on the Force .26?

You are mistaken sir.

It comes with an Ofna Force P4 .25 w/rcoil engine.

http://www.ofna.com/eng-force-25.html

Shut up, private J/K

Take a look at the OFNA Kit Matrix, an you'll see the included engine is the Force .26

Alright. Go to www.towerhobbies.com and type in mbx pro... look at the specs, its a .25

I have heard that this engine (.25 Ofna) overheats, looses compression fast, etc.

What is a good engine with good speed at a good price? And I do mean GOOD speed. One that will last me long...durable

Thanks!

I have mbx pro, which i bought in december.
As far as i know, now MBX pro and lx pro come with the new 26 engine.
They still have same boxes where it says that it comes with the 25, but they put a little sticker on boxes where it states NEW 26 engine.

PS. If I were you, I would not think about selling the engine and getting a new one. There is nothing wrong with the force 26, for me it has been great, not a single problem. Very powerful and runs great.

Sorry about my english, thats my third language.

Have fun, thats a good buggy for the money.

I can guarantee you that its the Force .26 thats included. None of the OFNA's are shipped with the .25, they stopped doing that some time ago.

Thank you so very much guys. vsustko22 your english is fine and you have reassured me and relieved a lot of worry I had about this purchase. Thanks for everyone that has helped!

I have heard a lot of talk about how engines loose compresson over time... now does this mean once you run it a lot and it loses compression that its time to throw the engine away? Or is there a way to restore it?