Motor swap question for future project.

[Aka_am]

This is going to be a project after the one I'm doing now..

But will a c125 motor bolt into a 250r? from what I can tell they are basically the same thoughout the years convering 125-250-500..just little stuff changed.

I would like to put a 125 into the R chassis, and make a removable subframe..and shrink it a bit in all aspects so it's not just a 250r with a 125 motor in it. And it wouldn't be done for awhile, a long project to do thoughout college, as money see's fit.


the only problem I can for see with this project is the exhaust. any ideas? (oh and I can also make mounts that's no problem but if it bolts in, well..... easy!)

[super90]

Why not use a cr250 motor? Theres alot more parts available and it would haul the trike around better than the 125 engine would. The 125 engine rips in a dirtbike but in a 3 wheeler frame I think it would be pretty held back.

[Aka_am]

well I'm doing a 250r now.. and if I where to do that, I'd just do another 250r or make a trike ala speedbumps idea..but change a few things.

I think the 125 in a 3-wheeler frame will still be faster then say a 200x, and might be about a 350x in power? (just not as much torque haha)

[cr480r]

Why downgrade in output? The only thing better than a 250 is a 500...

[Aka_am]

I'm not going to replace the 250r I have now, that's a total differant project, if you know that then, I don't hasn't been done? I mean that early 80 125 was, but not a liquid cooled pv motor, or anything.

I would like to do a 500, that would be tits lol but I don't know if I could handle the power right now (when this starts i prolly could though lol) but's the power like? anything to compare it too? The fasted thing I've rode is a banshee..and it was ok. good on acceration but not torquey at all

But....this is a 3-wheeler and they are wheel popping machines. I don't want to barely hit the throttle and be looking at the sky..and to fix that I'd have to extend the swingarm and for trail riding I think that would be bad.

And if I did do a cr500, it would be a newer model..there's always a 450r conversion. I just would do it differant then the 450rHRC conversion, as in less cost. lol

I'd like to do a 450r conversion, it'd update the 250r alot, more then likely I'd be cr forks on it for usd, and 450r swingarm..totally update it, removable subframe. I think cr125 forks would be good there longer, so I'd put a +swingarm on it too even it out, and that would fix the ground clearance, and I'd lower the shock, and subframe, so the seat height was the same.

[TwoHundredEx]

Are you set on the 125 motor? I think a KDX 200 would be perfect for that. Much more power than a 125 and still lighter than a 250.

[Aka_am]

I'm not set, on it. I'm set on using something newer, with more part avability and either a smaller motor then the 250, or something like the 450r

I'll look up kdx specs now, thanks for an idea! 37hp 34.3 nm so prolly about 250r speed in a 200. Does honda have a comparable model?

[TwoHundredEx]

37HP? Holy hell, I didn't think it was that high. Sure that wasn't for the KDX220?
I had looked it up before and thought I saw 27hp for a stock '95-02(?), which is the same as my 175. And I can tell you, even with my hacked up exhaust, it still rips, so that 200 would scream in there.
I don't think Honda makes a 200 2 stroke, they really should've though.

[Aka_am]

yeah i think it's more like 27hp my self..i see conflicting numbers between 27 and 37...I think if it is it's at the crank.

I also saw a ktm 250sx..