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Has any body ever wanted a wider transmission? I am doing a new build with parts from Kawasaki to change the trans ratio spread from the stock 3.3 to a 3.65., Should have it finished up before Xmas, Will update then on how it works
Here is a Pic of the new gears installed in the case,
I can't see having a wider ratio transmission is going to improve anything on a 250. But, I'm not a'gin it!
Now if you can do that on my 790R, we can start a conversation!
So a deeper 1st and a taller 6th. Better on both ends. Now toss in the multitude of sprocket combinations - I like the idea a lot.
What did parts cost and from where did you source them? Also, scale of 1-10 on difficulty to install? Based on the 1st picture, looks like a 12. But maybe looks are deceiving?
Last edited by ForestThump; Dec 3, 2021 at 04:55 AM.
Yes, it is a full teardown, I have done many transmission teardowns in the past so once I started researching the parts it was a no brainer for me to dive into my bike, This bike started out as a 98 300R and I bought a 2007 KLX250S cause it had the E-Start, and most all the parts where interchangeable, so I mixed and matched, but always felt a wider ratio tranny would be very cool, so I started looking through Kawasaki parts books, the parts I used are all KL250 parts, You have to change one bearing on the clutch side case and a new Idler gear from a Pre 2002 KLX300 if you also have the kick Starter installed.
It's a shame no company has the courage to do a seven speed. That could bridge all the gaps without changing sprockets. If you ever have the opportunity to ride a 7 speed do it. Kind of enlightening. I got to ride a Hercules 250GS six days model. That thing could run any trail and very likely pull 100 mph. I was impressed and still remember it in spite of it being about 40 years ago.
Yes, it is a full teardown, I have done many transmission teardowns in the past so once I started researching the parts it was a no brainer for me to dive into my bike, This bike started out as a 98 300R and I bought a 2007 KLX250S cause it had the E-Start, and most all the parts where interchangeable, so I mixed and matched, but always felt a wider ratio tranny would be very cool, so I started looking through Kawasaki parts books, the parts I used are all KL250 parts, You have to change on bearing on the clutch side case and a new Idler gear from a Pre 2005 KLX300 if also have the kick Start installed.
that 2007 klx250s already has a much wider ratio tranny than the 300r. The 2006 and 07 (gen I) klx250s have a taller 6th than the 2008 and beyond klx250s. So, even if all you did was swap transmissions, you'd be happy. But a fresh rebuild is always good.
that 2007 klx250s already has a much wider ratio tranny than the 300r. The 2006 and 07 (gen I) klx250s have a taller 6th than the 2008 and beyond klx250s. So, even if all you did was swap transmissions, you'd be happy. But a fresh rebuild is always good.
Trust me the KLX300R and 2006/7 KLX250S have the same tranny, Verified by part #'s and ratio's, and the physical parts in hand, 2009 and up 250's and 300's do have a lower 6th, never could see why they did that. But with this swap I will have a wider tranny than any other KLX 250/300 and can't wait to try it out, should have it all back together ( the Engine at least) this weekend as my final parts came in yesterday, Still are going through the forks and suspension bearings, so it will still be a couple weeks till I test it out.
Wide Ratio Transmission?
