250R or 450 or... both?!

[jdd3098]

Here's the deal. Back in the day, 2 years ago, I use to have a 416EX. I did MINOR racing and a lot of trail riding. It was quite powerful, torquey, and reliable. Before that I had a warrior and even before that I use to have an 1984 ATC 250R. I tore the 250r motor apart and rebuilt it. Ran great, lots of power, but it was a ATC, not a quad. and not liquid cooled.

I sold my 440EX for college tuition. I am in need for that rush again. I am looking to get a 1987 250R ( That is the year I was born, so I really would like that year).

Now for my question. Is there a way to have a 250R and a 450 hybrid in the same quad? I'll elaborate. I could have the 250r motor all set up on the track and race it. Then at my house, just simply take out the 250R motor and stick the 450 motor. Like swap them as I see fit? Yea it would take a couple of hours but could there be a less "perminant" engine swap. I would have have both motors on hand to just take them out and stick em in. I love the ripping power of a 2 stroke (as well as their bad *** sound), but love the torque and reliablitiy of the 4 stroke.

I am pretty mechanically inclined, so I know i could do it. Would it be worth it? or should a 250R be just the motor to leave in it and not fix it. My father told me all my life "If it isn't broken, DON'T Fix it!" Thanks.

[250Renvy]

I think it could be done, but would be best to do it on an aftermarket frame -
specifically a no-link or stock link.

I am getting a custom frame to be able to that exact thing - but it will use a CRF motor.

There are actually a couple JRD frames on ebay right now. They will be a bit pricey, but probably still the cheapest and most effective way to be able to put different motors in. The JRD's are setup for 250R, CRF 450 and YZ450F.

[jdd3098]

When it comes to frames I really don't know what I'm doing mechnically. I just threw on some a-arms on my ex, but not much. You mentioned a JRD frame, is that the frame or sub frame? How much do you think that is run me? Will the CRF450 (with engine mounts) bolt in effeciently? Just want a 250R half hybrid =). Keep me posted on your new custom R as well. I am very interested to see what you do with yours.

[250Renvy]

The hardest thing may be the fabricating if you aren't a professional fabricator / finding someone with the knowledge and willingness to take on the project.

Then you have to factor in that it will likely cost you $1500+ for a TRX/CRF motor with pipe, carb, electrical.

[baldathoR]

With the extra time and money you spend making this possible, not to mention the time switching them regularly it would just be easier to buy a back up turd.....err 4 stroke bike.

[All250R]

When you're talking about reliability and 4stroke and 450 in the same sentence reliability is not usually the positive part of the statement. There's a difference between an XR motor built for reliable, economic, fun torque and a 450 engine. Just like there is a difference between a civic and a ferrarri motor. Both are 4stroke, but we all know which maintenance bill we'd rather pay.

2strokes are better at cheap, light, high performance power. Run a 450 motor because you love it, not because it's reliable.

[jdd3098]

Gotcha. With my fiscal situation, I'd run a 250r for a while and look for a CRF450 motor for a while. I need to also look for a better frame as well which is goona set me back. This project is going to take a while, but I REALLY want to do it. It sounds fun to race and do trail riding with two seperate motors. And if I don't like it, i can just sell one of the motors and upgrade the motor i keep. Thanks for all your help.