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500 or 650 motor swap???

1574 Views 6 Replies 4 Participants Last post by  Racer X
ok so i know i have lots of plans 4 my bike and need 2 get started but im thinking on doing something completely different, with a different bike (still 250r) and just do the basics to my bike and just keep it and everyday rider and do my crazy mods to the project bike....

But back to my main topic, i am looking into getting a 250 frame with clear title, and either put the 500 or 650 motor in it, i know sportsi put in the 500 so its possible, but im thinking on the 650 for the fact of efi, becasuse i would like top make a complete custom stunt/everyday rider ( and when i say complete custom i mean exactly that) and efi for a stuntere is much better, i know i could get an efi conversion for the 500 and probably would for the stunter thing.

im not worried about body work fitment as i will be getting a faring set from tyga performance for the older 250 and mod it to fit the bike when done, but main plan is 08+ 250r frame, yamaha r6 usd swap, yamaha r6 swingarm swap, 500 or 650 motor, custom stunt cage, custom subcage, custom round bar, sprocket set (depending on motor changes set), rear set, rear handbreak clipons, ect.

Big question is ex500 with efi, or slightly smaller (dImension wise) 650 motor with stock efi.

this build will take a while and cost $$$$ and i know that most probily wont agree with what i wanna do to the 250 as alot would b changed, but i really want to break the limit as to what is possible in customizations, everything i want to do is possible especially with my knowledge of fab and mechanical skills, just looking for imput as to what the general people would like to see, and for the other top mechanics, fabricators to chime in and maybe bring up something i may have over looked....

Many thanks in advance, and if your going to bash, trash talk the project please dont post.
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Good luck with the idea bud, but I think you may have to narrow down the chice of engine to the 500 for a stunter.
The 650R engine is a semi-dry sump. From what I understand, the engine can starve of oil when doing wheelies etc.
Something to consider!
thanks, that was something i over looked cuz i belive you are right, since the begining of thinking up this project, was leaning more towards the 500 anyway, just wanted to get some input on what one others thought 2 be good to use, plus the thought on the project all together
The ninja frame will not like stunting. If you can cradle the engine to support the steering head it would help. The 250 Ninja brakes will need to be upgraided.
Work frame bracing into your list of "do-tos". The 250 frame might not like the extra torque.... As Racer X said, you'll need to consider a double-disk front end, maybe an entire swap off of like a ZX-6R or something, resprung for the appropriate weight, etc. Off-hands I can't think of any other issues - I'm sure you'll find them as you progress with your project...

If you want to move the limit to custom fabrication and such, you should do something that hasn't been done instead of another 500.... Why not something like a Ducati 916/996/998/748 engine? It's narrow, although it's large, and it has fuel injection?
i intend to do some frame work as well and i will be doing a front usd swap takeing esentially the entire front off of the yamaha r6 (usd, triples, breaks, etc.) to give myself adjustability, better breaking etc. so that the bike will take it. just as i have been thinking on more of the 650, as i am trying to do something a bit different cuz i really dont wanna copy sportsi with the 500 but the semi dry sump and non tunable efi may cause a problem with stunting, unless i can manipulate the oil pickup so that the 650 wont starve for oil then im going to go that way.
and i plan on building this with 90% salvaged parts and my local yard only deals with kawasaki, honda, yamaha, susuki, and very few harly's so ducati is not much of an option, plus i would like to keep it as much of a kawasaki as possible. the idea is good could probly be done as the ducati's are basically a v-twin, just on its side so its called an L-twin so it would be narrow enough but height amd depth may encounter problems, would need to have a good look and get measurements 2 know for sure.
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light oil in the fork might help. I dont have much expertiese in the way of setting up a stunter, But keep us posted.
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