Well, I hear what you are saying there...

But it's not exactly like that.

The 450R engine is an entirely different animal in the engine department.
Liquid cooled and everything... just totally different.


Some people seem to be getting good service out of their big bore EX's.
A lot of kinks have been worked out in 10 years.

A build like that might last longer between rebuilds than a 450R if all goes well?

 

I hear a lot of bad comments on the 440 kit, I bought one used for my son a few years ago,after getting it home, it was obvious the former owner beat the hell out of it, bent rims, dented a arms and burnt up brakes,and a White Bros. muffler that had burnt out all its packing,and the core was just rattling around inside. After a good cleanup, replaced a few damaged parts, even made a new core for the muffler and repacked it, it runs great, lots of power,my son ran it hard, even raced it a few times, without a single hiccup. I am beginning to think the "reliability" problem is with the engine builder, not the engine. Take any shortcuts,and it will come back to bite you in the a$$, do it right, and it should hold together fine. Just make sure it is jetted right, maybe add an aftermarket oil cooler,or extra capacity oil tank, and put a top quality oil in it, and you should be good. Over 3 years with not one engine problem (did have to replace the battery) makes me confident to go "far from the truck" any time I want.

 

Dam that looks nice. AND fun.

 

A more ignorant statement has never been posted!!! You need to do some homework....

The 450 is not just a bored out 400EX. The 450R engine is most similar to the CRF450X dirt bike engine. Both the CRF450X and the TRX450R are multi-time Baja 250/500/1000 winners (as was the 400EX before it!), so you know these engines are dead solid reliable and can go the distance. It is a "thumper" engine that uses formula 1 technology, and very different from the old tech air cooled XR400/400EX engines.

Read about it here: http://www.belray.com/scripts/future...0-f562d5812296

 

ALL The 450s sport ATVs from every Manufacturer are from there 450 Motocross line. These engines are for performance not long term readability. Your just not going to get high hours out of a motocross motor without a rebuild,its just the nature of the beast,but you will have fun. Sure they run a Baja race but you can bet it will need a rebiuld before it runs it again.

I hang with mechanic who races 450s and rebiulds his top ends every 100-120 hr and that pushing it he says 50-80 hr what the more advance riders do.

Thats why the dual purpose off/on roads motorcycles use the mellow motors and not there hard core performance motocross motors because people expect to ride them trouble free for thousands of miles for years.

Case in point the Suzuki DZ400 street bike uses the same more as there z400 ATV not the motor from there wilder R450 ATV or RM450 bike.

 

lol

 

a ton of fun gets a lot of looks too!!!

 

TLC... where did you get the shield just above the back side of the foot peg? I've burned up two pairs of over the boot pants on the pipe where that shield is.