650L motor in CR or YZ frame?

Anybody done this conversion, I was wondering if the 650L motor will fit in the aluminum CR250 frames or the steel YZ 250 frames, I am considering buying a 650L if this swap can be done to make a much lighter bike that is still air cooled (no radiators to bend) and has electric start. My thought is that i could put the battery where one of the raidators goes and a oil tank where the other would be. Thanks for your input. How much weight do you think I would really save if this is possible. I'm leaning more toward the YZ frame since steel is easier for me to weld. thanks again

I think that you will find that the engine is just way too big to fit in the available space.

I too think it would be too big. I think fitting it in a XR650R frame would be easier.

I too think it would be too big. I think fitting it in a XR650R frame would be easier.

The problem with using an XRR frame is that it is heavier than the stock L frame. The 650 is near the same weight as the old 600 it relplaced with a motor that weighs 10 lbs less.

It may be possible with LOTS of work to wedge it into a YZ frame, as the twin spar CR frame would not be wide enough for the head to fit between. You would need to completely fabricate a new aluminum cradle that sat a little lower, and possibly some work also at the swingarm pivot. It can be done, it'll just require more work than the average person would want to do. But if you really love the idea, time and money are not limiting factors.

Nuthing in life is impossible ........ but alot of things just aint worth it.

Have you ever seen a dirtbike (not a hill climber) with a Harley motor in it??

Nuthing in life is impossible ........ but alot of things just aint worth it.

Have you ever seen a dirtbike (not a hill climber) with a Harley motor in it??

If I had a smaller boat, so I did not need a full Harley for the anchor, I may put the Harley motor in an old dirt bike frame so it is easier to wheel around on the deck before I drop it in!

If I had a smaller boat, so I did not need a full Harley for the anchor, I may put the Harley motor in an old dirt bike frame so it is easier to wheel around on the deck before I drop it in!

+1 on that!

There's a bunch of alumnium-framed XR400s running around out there. If memory serves there's a few pics on the BBR website.

I've always thought that it would be neat to have an alumnium-framed XR600 and figured if I went into full-on NASA mode I could make it work (keep throwing money at it until it works), but came to the realization that I'd end up with an alumnium-framed bike with a 100lb motor.

Maybe the fun isn't actually riding something like that, but building it?

"O"

Maybe the fun isn't actually riding something like that, but building it?

"O"

:busted: We have a winner!:busted:

This is why I am planning to build a 500AF in the near future. Shure, I could buy one that was done, but where is the fun in that? My buddies and I like playing with milling machines and welders!

Back in the day, I always wanted to shove a KLX650R motor into a KX500 chassis, but I always wasted the frames of my KXs before the motors!:cry:

I have an '03 YZ250F rolling chassis and I've taken a few measurements from different engines to see what might be a good fit. A 650L is pretty-much a no-go, but an XR400 looks like it might be a good candidate...

i'm not sure i'd bother trying to put that motor in another frame, i have an xr650l with cr forks and some other mods and i'm really happy with it. you can actually take a lot of weight off of that bike, theres a lot of parts on it that you don't really need, i was really surprised with how much stuff came off. it seems like every time i mess with it i find some other little useless bracket or something that i can take off. i weighed the box of take off parts and its over 30 lbs!!

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