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I found a thread from a while back where a guy asked about swapping the 450r flywheel (22oz) from 02-08 into the 250r (16oz). There was no follow up, but I have found several 450x complete electrical swaps. My question is this a direct swap? Seeing how I can’t track down an entire trail tech kit and steahly no longer makes the weight kit it seems like the easiest, fastest and most cost effective route if it works. Has anyone done this swap or have any info into it? I have sent a pm to shaggy to follow up but don’t expect to hear back since he hasn’t been active since 2012. Thanks in advance.

Welcome to the site !!

From what I have read on the interwebs , you can(I am not 100% saying it will fit , just that from what I have read it will) use any earlier 250R or 250X or 450R or 450X flywheel (earlier meaning , not current gen , and not 09 on 450R)

That’s what I’ve gathered too I was just wondering if anyone aside from the guy I messaged had done the swap. Guess I’ll find out my 03 450r flywheel showed up today lol.

What you are going to have to determine is the weight differences between the flywheels , compared to yours , as different weight will do different things to the power delivery ... my 2020 450R had a serious amount of torque throughout the power range , the flywheel weight I put on it tamed it down to where my 61 year old body can handle it , and actually ride it aggressively now ... unfortunately , they only make 1 weight due to clearance issues ......... and no one makes a flywheel for it .... so I have no adjustability ......

So what you might have to do , is if it fits well , and actually runs good ..... then ride it and determine what the change did and if it is too much , or not enough .... any heavier weight change should make stalling less prevalent , and will take away some compression braking (that was a major plus on my 20 , it would almost throw you over the bars coming into a corner and dropping to 2nd . now I can take the same corner in 3rd and faster and smoother) , but depending on your needs (track or trail riding) you might like it , or may want a 250/450X flywheel instead ..... Report back with your results , as there is minimal info out there ....

I would go heavier if I could but can’t find any setups and don’t want to do the full 450x swap as the stator and pickup are completely different. I emailed staehly to see if they had the cam files still but no dice. Oh well Should be +6 oz with the current plan. Gonna degree out the magnet to see if I’m losing or gaining timing, I’m guessing Honda didn’t make any adjustment there and used the icm to make that correction. Next step is a new bike if it doesn’t do what I want .

You can always have a machine shop make you one - just give them the dimensions and weight you want.
There is really not much to them. I made one for my YZ out of a stainless on a lathe.