I used to own one of those little rippers!
My suggestions:
1. rejet the main to one size smaller (310 on the Mikuni carb)
2. replace the muffler with a straight thru unit.
3. if you can find an after-market pipe, get it.
4. DON'T bore it out to a 240, you'll ruin it !!
well, that's it - not much trouble, hey! I never bothered mucking about with the suspension, someone else might know more about that than me.
Most everything is stock, except UNI filter. The stock pipe and SA are currenty on the bike. I'm looking and FMF or DG pipes. I'm interested in any and all mods.
TBoyd, What do you need in the way of direction?? It's quite a simple job. Stock gearing is 13/48. 108 link chain, I think. get an O-ring chain and plain steel sprockets - JT do the job well.
jju67, I don't think FMF made a pipe for the aircooled bikes, but I've heard DG did, although they may be a bit hard to find (well, over here they are anyway)