Anyone swap a cr250 motor into 2nd gen 250r trike frame?

[kevin]

A friend is looking at doing this swap and I'm just curious if anyone else out there has done it and how it turned out
I believe the motor is an 1986 vintage

[kevin]

Just found out the motor is actually 1998. By the looks of things he's gonna have to do a lot of hackin and slashin

[Gabriel]

Not the least of which is, the kick starter travels the wrong way. It's "DOABLE" but it's gonna be a pain.

[kevin]

I told him about that but doesn't seem concerned he got a roller for practically nothing and this cr motor came available on the cheap so he wants to make it work somehow.

[BOB MARLIN]

Radiator room ?

[350for350]

I believe that the 1st and 2nd gen 250Rs both were right hand drive while the 1998 CR250 is a left hand drive. The side of the drive is where the chain is at. I'mnot saying that it's a project stopper, but it's still another obstacle.

[yamaha_ripper98]

With all the changes required to succeed with this build, it’s likely to cost more than expected to finish. Or if the plan is to use whatever works that’s laying around will be a strange contraption to say the least.

the kickstarter will be the easiest. Just trim the fender for rear kick room.

Converting it so the chain is on the left will require some fabrication and part movements.

Exhaust is likely to be awkward as the cr is on the right and the r is on the left. Challenged most by placement of the radiator/s depending on if it’s chosen to use both or just a single. The silencer will be simple.
Having a header that seals on the exhaust port decent and has a proportionate size fatty to stinger and the bends to work and retain desired powerband rpm’s.
The Power valve will help with the engines bottom end regardless. But if the header isn’t working correctly the valves timing could be effected. Only changing the spring weight would correct the timing for the flap.

Just tossing in a engine of the same size and from the same manufacturer seems easy enough at first. But without proper measurements and a plan to overcome required modifications normally result in abandoning the project.

The build extremely likely could be done.

I personally wouldn’t consider doing this with a early 250r frame unless it’s been severely abused (cracked and welded or severe subframe damage from a nasty crash) and has no use to anyone that is trying to restore a early atc250. Enough older trikes get chopped and scrapped for no reason by people that think they are worthless.

It’s not my decision however, so best of luck with whatever is to come of the build. If it’s decided to continue post pics and show the progress as it will be interesting to see the completed build and how things are positioned and changed to overcome the issues.

[oldskool83]

counter balance motor vs non....you will hate yourself. your hand will be numb...don't think it will happen it does. I could feel it with a KX112 motor in a 200x. Don't put dirtbike motors in atv frames if you want to ride them more then around your yard.

[kevin]

Never even thought about the counterbalance issue guess we'll see
The exhaust I've seen people run out of either sides of the bike like when guys put on fmf expansion pipe from a 3rd gen with no issues so hopefully won't be too bad.
With sprockets being on opposite sides I was thinking he could possibly just flip the bearing carrier around and hope for the best.
I'm just not sure about room for rads maybe somehow put in a 85/86 tank?
Thanks for the comments guys!

[oldskool83]

Part it and buy something else. You will loose your butt in costs when doing this, even if parts are free. I've built 2 bikes a year for last 10 years. Its not worth if it. You cut them up they are worth nothing. Keep it stock. Sell the CR250 motor cuz some guy will buy it for a AF conversion. Then buy a 1st or 2nd gen motor and built the bike.

[atc300r]

Radiator is simple get a first gen Tecate rad mount it to the triple .Fred Morrell did this with his crf 250/200x trike.For rear sprocket pull the bearing carrier out put it in the other side.