i have a 250x 87 in great condition and i got my hands on 250r motor and plan to put the 250r motor in. i know that there is going to be some hectic mods to be done but im ready for anything......any advise? help

 

My advice to you is put the R engine in an R frame. The R engine will overpower the X chasis in every way imagineable. Besides it wont handle as good as an R without some serious chasis and suspension mods. If you're gonna throw anything in an X or EX chasis your best bet is to throw in a 350X engine.

 

is the 350x motor a bolt on? 2 or four stroke?

 

The 350x is a pretty straight forward install, much easier than the 250r, like Need said, the power is all wrong for the frame, kind of like putting a 500hp big block in a Yugo. The only major mod for the 350x swap is a notch for an oil line in the frame near the top left side of the motor ( I read about a swap in a magazine article once).

 

I agree about the r motor not in a 250x chassis. I have done the 250x/350x conversion and it is fairly easy. It is a good conversion but unless you can get a 350x motor fairly cheap I would just sell the 250x and get a used 400ex. I had tons of modifications to my 250x when my engine blew, including a 250r front end, so I kept the x.

Here's a good website on the conversion.

trx350x link

Hope it helps!

 

Oh........And if you need a 350X engine, I have one.

Brand new, never cranked.....with carburetor and oil cooler.

$1200.00

 

Never cranked isn't neccesarily a good thing on a 16+ year old motor. Especially if it wasn't stored with oil. Plan on atleast a new clutch, I can come up with more if you'd like.

I paid $900 shipped for my crate motor of ebay.

Something else to consider is that 350x parts are going to be harder and harder to come by. Being that Mr. Honda died awhile back (maybe a decade?) and his rule to always have parts available died with him when the lawyers took over. So no more 350x parts.

Leave the 350x motors for the die hard 3-wheeler guys and get a used 400ex.