Tip Top advice from Mr. Fontyyy there I think. As the man said, just buy yourself some new rings etc. and get stuck in - you might want to consider doing the little end bearings while you're in there too? And taking the cylinders off will give you an opportunity to get an idea of the condition of the bottom end as well.

I still remember the immense satisfaction I got from doing my first stroker top end at the age of 13 - nearly 25 years ago with not much more than an adjustable spanner and an old screwdriver . It was an aircooled single so it was even easier than a 'modern' water cooled bike like the NSR (A yamaha FS1-E in fact), but the sense of pride and achievement when I fired it up were enormous. It wasn't long after that that I did my first bit of 'tuning' of course ...and not long after that that I was rebuilding the top end again.

Dive in. If you post up any queries along the way, the good folks here will help you out. I can't imagine that there are many of us that haven't rebuilt a number of stroker top ends. And some on here can prob' do an NSR in their sleep - not me tho'. Being an NSR newbie I'm yet to delve into an NSR's innards. I have to say though that the motor looks to be the easiest of all the 250 strokers to work on ( as Andy notes). It really is a delightfully uncluttered design (Wb sings praises of Honda shock! )

Be warned though. It will probably give you a taste for fiddlling and fettling stroker motors that may well take over your life.

Good luck with it

Wb [/i]