ATV Florida Forum

Well it started a 2000 400ex then became
A 2003 crf450ex

Its got fully houser and axis susp
Douglas and itp
A custom pipe

And alot of  HR racing customs..



(http://i10.photobucket.com/albums/a127/RC10GTBOY/janelle2111.jpg)

(http://i10.photobucket.com/albums/a127/RC10GTBOY/janelle2108.jpg)

(http://i10.photobucket.com/albums/a127/RC10GTBOY/janelle2110.jpg)

(http://i10.photobucket.com/albums/a127/RC10GTBOY/janelle2112.jpg)

Looks good.

very nice.how fast would one of those go?

Idk for a top speed but i do know the power this thing has i wouldnt switch back to my trx450r or my yfz
This thing is ungodly

that bike looks sooo nice

Mondy i gotta order my graphic kit a tc pipe chain rail for the bottom and some other odds and ends.

 :o That thing is nice.  Can you just bolt up the dirtbike motor or do you have to get a frame custom made to fit it, but still be a 400EX chassis?

Very nice!!!!

thats awesome! i bet its a blast to ride.

Well tested it today at bartow and all i can say is HOLY SH!T
This thing is crazy..
And thanks everyone for the comments

And no u have to buy different motor mounts and customize the frame a little..

But still a stock 400ex chassis

id take that over any quad.
thats some insane power

oh, no worries, i'll take one off your hands.  ;)

Did you finish paying for it yet?

yep

Working at a Machine Shop helps alot when you have to do stuff like that.... MUCH Faster than the Reg. 450

And finaly the builder chimes in

Looks good...I like how they did the radiator.

the Radiator is an aftermarket YFZ that was a NASTY 500 Bucs !! 
the Vids look cool Walsh....GIT IT RAGGGGGGGGGGG !!!

That nasty radiator also has a tiny  hole in it..
C&R might not be that great...
Nothing a little tig welding wont fix..

What makes the crf450 a faster engine than the trx450?

It's a 2-stroke.  It would be like having a 750-800cc 4-stroke in a 400EX frame.  That thing must really haul-balls!

its not a 2 stroke

Its a CRF450R FOUR STROKE

I need to read a little better.  I guess all I saw was the CR.  My bad.  That does bring up a valid question; why would the CRF motor be any better than the TRX motor?  The TRX motor would be tuned to move the heavier weight but the CRF motor would probably have slightly higher power up top.  I don't see a huge advantage there.  Now you have to admit, a CR450 (or 500) motor stuffed into a 400EX frame would be very interesting.

Pretty sure its the bore and stroke.

450r engine is 96.0mm x 62.0mm
cr450f engine is 96.0mm x 62.1mm

But... I ask myself the same question all the time.

So they share the same bore and stroke; no advantage there.  Obviously, the only difference is in breathing and, most likely, flywheel weight.  For the added weight of a quad, I think a wider power band with more torque would be more useful than a motor tuned to move a 200 lb dirt bike.  The CRF motor can't have much more than a few HP advantage on the top end.  That's great if you're running the dunes but last I checked, we don't have too many dunes you can ride on in Florida.  All that aside, though, it is a very clean conversion.  Good job.

crf450 motor has higher compression, geared differently, etc   

think its about a 15hp difference over the trx450

Nah, they run the same compression also. And the only thing you could keep for the gearing on the quad would be the 13t sprocket up front.. Because I believe the bikes run standard around 48 whereas a quad runs 38.

quad=12.0:1
bike=12.0:1

for some reason, I could believe the lighter flywheel theory.

Actually, I did a little research and the CRF motor has about 11 HP on the TRX motor (50 vs. 39).  I also saw mentioned that the CRF motor does have higher compression.  Not that that is a good thing; remember, with the higher weight of the quad, you will be putting more load on the engine in low RPM situations which invites detonation.  Also, this goes back to the flywheel situation.  I would almost be willing to bet money the CRF motor has a lighter flywheel which would put even more load on the engine in low RPM situations.  Again, though, it is a very clean conversion and I'll bet money it is WAAAAYYYY more satisfying to ride than the stock (or even modified) 400EX was.  I'd take it for a spin!   ;D

Its awsome the gearing is great i have a 14t ont he front and a 36 on the back..
I also have a 13.5.1 piston..
Im having stainless valves put in it now..
I dont really like they way the trx's feel i have one but done hardly ride it..
The 400ex feels alot better and handles great.
I love the combo its a blast to ride..

I was lookin for ya at Croom Sunday.Did you go?

No my freind made a track on his job site down in vinice so i went there and rode..
I wanted to go to croom bad but glad i didnt go because my bike took a poop..
Got the vales being set right now ill have the motor back thursday tomorrow and ill be ready..
I might go to hardrock saturday with trx#9 and a freind..
But i got another hyrbid on the way.. :) i pick it up monday..

;)