The 3 jaw chuck on my 12" lathe won't grip the outside of the pulley, I am using the transmission shafts from a Ninja 250 to make the mandrels, they are the same size spline.

To cut the backside, the mandrel uses the Kawasaki bolts to fasten the pulley onto the Mandrel.

I use a second Mandrel to cut the face, and it hold the pulley using the outer surface.

The shaft of each mandrel is just short enough that they don't extend out to interfere with the cutting.

I will post some photos.

If one were to fit an 18in rear wheel with a 140/80 tyre, the swingarm will need to be extended a little. The rear pulley off the Z750 could help move the rear wheel where the tyre may not interfere with the cross-brazing, allowing the mentioned taller overall rear wheel..

Good idea. Ideally, one would probably want to have a different, lighter swingarm instead of the heavy steel item. A lighter wheel would also be beneficial. Then again, all these things make for an escalated cost and/or machining requirements.

Hi Team Suzuki Savage!

This general idea of longer legs is great! Nothing has changed since my moped years.

I did not drive my 2004 much before I took it apart and converted it to a sit-up-and beg -roadster of my liking but now with this 25 tooth mod, it is a very calm and collected steed in deed. 1st gear felt a bit long in the beginning but now I am fully used to this. The EN500 pulley was $12 on eBay including shipping and I found an Intruder bushing (as a backup - I did not need it. It has the same part number) for $25 with shipping. The HF drill press was on sale for $69 + tax 6% ( I should have bought a baby WEN for $10 more - the spindle on the HF had 1mm of play, needing some creative crimping - now it is not so bad but took me a day) and the drill press wise was $24+ tax, The HF 125mm angle grinder was $17 + tax, the cutting and grinding wheels I had and flat bar. Not so expensive and the souvenier drill press and grinder are mine to keep! Garage walls etc. have a gray hue from grinding - this is a budget build.

The pulley's price included loose rivets on one side of its belt guide - I hammered the worn-out rivet ends flat and the pulley has been silent so far.

I did this conversion somewhat differently, please feel free to comment. I took some pics in the process, see below. My lathe-for-the-poor does not reserve a picture, only the final product can be published with modesty, as in 'good enough'.

The difference in my method from the previous is that I gained 4.5mm more spline width by turning the Kawa pulley around and instead of having to machine that  sides of the pulley down to Suzuki's 15mm width from the 19 achievable, I cut off 4.5mm from the bushing that usually covers part of the splines. Then I only needed to machine off some 8mm from the new 'nut' side. As far as I can tell, the Kawa pulley is not 'handed' but behaves the same in reverse rotation as it does in normal rotation. In this Suzuki application, the Kawa's shaft locking method (two M6 bolts holding a toothed washer) is not used and Suzuki's locking method of bent ear of the toothed washer works just like on the old Suzuki pulley.

The advantages of this method are quite clear, at least to me - 35-45% less machining work and 15-17% more spline width. I am not a machinist over basic angle-grinder-and-drill-press -level so this method is really a big advantage to me. The pulley shaft gasket bolts etc. need to be changed to low-profile ones anyway and the aluminum pulley cover needs some rib grinding no matter if the Kawa pulley is used in its narrow spline form or wide like proposed here.

I don't have a lathe so I improvised one from HF products. Kids, do not do this at home -parameter is set here - you need your eyes and limbs for yourselves. Any machinist can do these cuts safely - the bushing is not made of particularly hard material but the pulley half needs some serious carbide bits - see the previous postings.
I was able to shorten the pulley bushing by 4.5mm by using my lathe- for-the-poor with cutting disk. Then, the Kawa pulley fit in fine, albeit now wrong way. Full 19mm spline width of Savage is now available.  

I was able to cut the pulley's rear side down by 8mm with the same contraption, now it is the front side. My grind-work hides behind the toothed washer and nail polish. I call it the high-friction finish.

The original toothed lock washer fits fine as I have about 1mm of the spline free for this, much less than the old pulley allowed but this works just fine - more spline for this purpose is a waste.

I added some Locktite on the pulley shaft threads and stepped seriously on the rear brake and tightened the pulley nut hard with a breaker bar, as it was quite tight originally. Without this breaker bar or impact driver this would not have worked - out with the old or in with the new. You guessed - I don't have an impact driver. I hammered the lock washer over a corner of the nut and smeared some of my precious nail polish over the joint to see if they move.  

Please comment! I just got the bike registered so I will report any failures - but I think this works great. Speedometer is of course showing potatoes - I use the RPM meter only for now as I need 8% (10%?) reduction gear on the speedometer or one operated from front wheel. More likely like that...

If you decide to use the same method that I used, please be careful and do this on your own risks and also, make your own measurements as I cannot guarantee the accuracy of my measurements. They worked for me but your mileage may vary as they say! Feel free to comment!

Cheers!
JJ