Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Welcome - it was probably me...Whilst its apart, you might as well inspect everything, although dead big ends are very rare. If the rings are in bits you need to check the bores as you may need to rebore before rebuilding.Keep us informed as to what you find (with pics if possible)Steve
check the heads not scrored to buggery by the bits (I've run one like that and it was ok but benefitted from a file to remove the high points), and go through the gearbox carefully as loose debris may go there too and it's a pain to rebuild an engine, put it in the bike only to find it's no good. May be worth a look at the oil pump - I always turn the engine over sans rocker cover on the rebuild to check there's plenty of oil getthing back through the oilways to the head. bottem ends normally ok and so far I've yet to have an engine needing more than rings on the bore front appart from silly things like rusty bores or relining (con rods make a right mess when they let go) In any case there are so many good pistons + barells out there used that I'd always go good used over rebore.
Just get oversize piston kits and have it rebored to suit (usually about
ebay for used barrells genrally, I tend to buy when cheap rather than when needed but I've had a few spare engines off there that have surendered good barrels and other bits for
Great to see another 500/4, not so many about any more. I've been riding mine since I rebuilt it in 1995. Welcome.