the only production exhaust that will fit is powroll that i know of. if you don't have anything to start with and are not a very experienced welder with a tig welded buy the above pipe for $330.00.

 

xcBansee is correct,

Welding on those little headpipes can sometimes lead into a disaster.

I am using the Powroll pipe on my TRX350x and it does bolt on with no problem.

 

I was in the local quad shop (STEVES CYCLE)and I noticed a 400ex complete exhaust from white bros.
It looked like the head pipe set up was able to be adjusted. If so that pipe system would be perfect for a rx conversion.

 

I was wondering is a 350x motor in a 250r frame worth it I would just buy a 300ex and get big bore kit and aftermarket suspensoin I think thatw would be better (in my opinion) than taking all the time and effort and building a custom 350xr

 

To me there are several advantages of doing the RX conversion VS the 300EX. First the wheel base on the R chassis is about 5 inches longer than the 300EX which will give you better handling. Second you get the racing suspension of the R which a lot better than the EX. To me you get the best of both worlds, you get the best racing atv in the world and the power and performance of the 4-stroke motor. Thats why I am doing my conversion.

 

Anybody ever thought of using a 400EX chassis for the 350X conversion. Every racer I know who ride both the R and 400EX say the 400EX is much smoother and handles better, plus parts are cheap compared to an R. Not only that, but you wouldn't have to modify the frame rails at all like you do and R frame.

I'm actually working on a YZ400F powered quad, and I was originally going to use a 400EX frame and plastic, etc. I am also using 250R hubs, axle, and brakes. A new 400EX frame and subframe cost's $480 ($600 for most people), and all the plastic with seat is only $250 (or maybe $300-350 for most). Why I say originally, is because now I may be testing a prototype chassis for an aftermarket company, so if that works out I won't need a frame. But even so, my friend is building a Leager's YZ426F, and he even said if he was to do it again he'd just use the stock 400EX frame for the cost savings and they handle very well.

It may seem like doing that would cost more if you already have an R to work with, but you can sell most of the parts you don't need for about the same or more than it will cost to buy new 400EX parts. Even if it costs a little more to build originally, in the long run it would probably be cheaper. Especially if your like me and prefer stock plastic for durability, which is outragious for an R and cheap for a 400EX...

I have had people say they don't beleive the 400EX handles better, they just think the 4-stroke engine must give that impression. But I do know the 400EX's are better handling than an R, because a national racer I race with used to have a WR400F in a 250R frame, now he has it in a 400EX frame, and he said that the 400EX doesn't beat him up near as much as the R did.

Just an idea for anybody else who may be considering this type of conversion.

Sickman

 

That is actually a very good idea Sickman

I did consider this before I ever got started on my RX conversion, but at the time I did not know what parts were switchable between the 400ex and the 250r. I did know that the a-arms would fit, but that was about it.

What I was scared of was buying a 400ex frame and then finding out that I then had to buy a swingarm, steering stem, footpegs, and all of those other little items that may be inexpensive bought seperately, but when you have to buy enough to make a complete rolling chassis then it really adds up.

Although I am going to be using 400ex plastic on my rx conversion. I have found out that the complete package (all plastic and seat assembly) is around $360.00 (what a deal !)

Anyway, I'm still not sure about the 400ex. If I were to buy a bare chassis could I bolt everything from my R to it?

 

No, the a-arms are actually a bit wider, only like an 8th of an inch, so you could maybe trim the bushings, or trim the pivot and use 400EX bushings. BUT, the 400EX top frame rail is wider, so, your better off just buying a-arms built for the 400EX. The swing-arm would work, but I'm using a bike engine, so I will run a 400EX style swing-arm, but A guy here in Iowa makes really nice swing-arms for $350 vs 500 or more and a long wait for a Lonestar or Leagers, etc.

And yes everything adds up, but like I said, you can easily sell R parts for about as much or more than new 400EX parts. Footpegs are only $15 to $20, you can easily sell R pegs for that. A stock 400EX steering stem only costs $50, you can sell an R stem for that. A 400EX chassis costs around $600 complete, a good R frame will easily sell for $500-700 depending on condition, and on and on. Also you won't be cutting and welding the main frame, which weakens the metal and will cause the R frame to break sooner than normal, plus its already 12 years old anyway, whereas the 400EX is new. I'm planning on using 400EX spindles with 250R breaks, but if someone didn't want to spend the extra money you can use the R spindles. Also I'm using all R hubs, axle, and breaks all the way around. Also, all or almost all the R hardware will work on it, so you won't need to spend big money for new nuts and bolts. Also if anything fails like the frame or anything, I can go to my local Honda dealer and buy a new part, instead of buying used parts.

Thats How I look at it.

Sickman

 

I am also working on a 400ex project bike, but this one is for my wife. She wanted an automatic four stroke SPORT bike with reverse. My son (ERNIE) installed every aftermarket part for his 400ex. So I bought a new 400ex frame and I am putting a pumped up 1986 200sx/x motor in it and all of his stock parts. It is the biggest chain drive auto/rev. motor honda made. My wife is in her late 40's and this should make her a good light auto sport bike. I had an old basket case 300ex and the brake calipers are the same part # as the 400ex. you might be able to buy used take off parts cheap for your project.

 

hey guys there is a 350RX for sale and I'm thinking about gettin it. if I go look at it what should I look for ....like problem areas......what about the chain? I've heard of problems with it. tell the key areas to look at......its only $2900 .......sound like a good deal??? I have a pic at my address below.....its on the second page...tell me what ya'll think of it........thanks