For those whom ever thought about doing it, I have put both the YZF and TRX250R engine in a 400EX chassis and it works awesome. I just had pipes built specifically for this and will make CNC Machined billet mounts available if there is enough interest. My quad was featured in the September 2001 issue of Dirt Wheels and ATV Sport Magazines in case you remember it.

I have one person already serious about the YZF motor, so please let me know if anyone else may be interested.

My name is Adam and can be reached at Sickman80@hotmail.com.

Thanks,

Adam

 

Where did you get the 426 motor and what was the cost? How about the cost to get the pipe made?

I would imagine if I could find a way to sell my complete motor it would shave a good chunk of the price from that swap, might even be cheaper than a $2500 fully modded 440?
Hmmm

Rod
02 400EX
86 250R

 

I know of someone who is looking for a spare 400ex motor. Email me at blaster668@hotmail.com if you want to sell it.

 

Hey Sickman, I saw your posts over on thumper talk, but I figured we would get booted out if we talked too much about the hated quads.
We used your article in Dirtwheels as a guide when we built my buddies YZ quad. What are you thinking on pipes? Just the silencer or the whole thing?
I'm trying to round up some parts to do my own conversion, and I might be intersted in the silencer if it wasn't to high. I want mine a little quiter than the TC shorty's that seem so popular at the nats though. Did you change your jetting much? Have you thought about a flywheel weight? that motor sure seems to stall easy, but maybe we can get used to it.

Sorry about the novel, let me know what you are thinking about the pipe.

 

As far as pipes, I have one made specifcally for the EX chassis and plan on jigging it up pretty soon. It has a reverse megaphone silencer. I know the stall, my pipe actually got rid of it for the most part, plus mine is jetted much different. I'm running a 210 or 220 main, I can check and let you know later for sure. I am also thinking about a fly wheel weight, i am going to ask a friend who has tried different ones to see which is best. Allot can be gearing also, right now I'm running 14/38, and for an indoor I put a 13 on and the thing was an absolute rocket. I actually was overshooting everything without trying, so I regeared it back. It would have been awesome if I was used to it, so will practice with it before-hand next time.

I hope to have a web site up sometime fairly soon with more details, because I am hoping to sell kits and it looks as though I will have all the details finalized in a few weeks now. It kinda stinks cause I don't have much time to do much with school, but am trying.

Adam

 

Adam, Hey this is Craig. I have spoken to you several times about buying your pipe for this conversion. I finally got my motor a few days ago. I believe I am going to give your pipe a try. I am going to build my own oil rezzy, can you give me any tips? Also, do you know if the stock yzf radiators will fit? I have them too, and hate to shell out more for a radiator if I dont have to. Thanks.

 

The YZF radiators are too tall. I use a stock 250R one right now, but am going to get Balwin Motorsports extra capacity one pretty soon. Make the oil rezzy be able to hold 2 qts, I looked at allot of ideas, but decided the L-shaped one under the radiator is best that I decided to go with.

Adam

 

We just got back from a 3 day riding weekend, inaugural ride on the yz setup. That thing will haul the mail!!!! I beleive a flywheel weight would be a great improvement, we ride in the woods for fun as well as racing, and climbing those big hills with ruts and roots is quite an experience with that kind of power.
We are using the 400 airbox with no lid and a twin-air filter, it seems to run pretty well and the stall is about gone, but it doesn't start very good hot. It takes four or five kicks if you follow the procedures perfect. If you let someone else try, it takes alot of cleanout kicks. I think that tells us the pilot circuit is too rich, but what I know about jetting is very small. Let us know if you get something going on the pipe.


One more question if you don't mind. Did you build a motor mount for the top one above the carb? How bad is the vibration on yours?

sorry that was 2 queations .LOL

Thanks

 

Sorry for the late response, just waited till I had them done. I am able to get the pipes made now, so if interested let me know.

Thanks

Adam

 

Actualy its a fluke that i come by this post. Im planing on doing the same thing. but first of all.
is the wr426f the same engine as the yz? what are the differences?
Anyway's, Im buying a houser 426 frame and elka's long travel system with houser long travel arms. Can you get me a pipe for this set up? and how much and what type of pipe? sorry about all the questions. But my walet will apreciat it if i only have to buy something once. hahaha