Looks like a worthy project.
Some suggestions if I may:
I recently started re-sleeving CR500 cylinders with Aluminum sleeves on the engines I've been building. The re -sleeve is
done by Advanced and I send the finished cylinder to Millennium Technologies for their version of NIKASIL plating. This gets
you a piston and cylinder that expand at a similar rate (reducing the possibility of cold seizures), saves a couple of pounds,
and benefits from a much more durable cylinder wall. I recommend a Wiseco or Wossner forged piston and make sure you
drill the two oiling holes for the exhaust bridge.
As others have alluded to, I also recommend a compression release. Larry Wiechman does a real nice mod that looks
factory. There is real merit to the claims of cracks in the case cover caused by kickstarter stress. The kickstart assembly
is a robust design, but the housing is a weak point over time.
Another item to look at is the clutch. You will find there is very little in the way of aftermarket support in this area. One of
the mods I like is converting the stock CR500 clutch assembly over to the CR250 version. This allows you to run all the hard
anodized Hinson components which will extend clutch life and performance.
I noticed you want to use TMR for the port work. It will be interesting to hear if his idea of a toned down powerband is the
same as yours. Also, very good idea having the crankshaft balanced. If you go with Crankworks, I recommend you send it
in now and if you're lucky, it might be finished in May when you're ready to start.
Finally, there is a real benefit in using the older 89 cases over the new ones. Over time, the tooling used is increasingly worn
and the newer cases have poor tolerances. Most noticeably, the amount of lash between the primary gear and clutch ring gear.
Your cases were manufactured the first year that tooling was used and as a result, should be very precise.
Enjoy the build.
dogger
