1990 yz 490

[bongo]

my yz is makin a little bit of top end noise what is involved in rebuilding the top end thanks. bongo.

[cr125rider]

depends on what needs to get fixed... the usual top end job consists of a piston, ring, pin, and circlips being replaced. and gaskets..... unless your crank is messed up then i cant help ya there.. sorry pal

[blaster 22]

What kind of noise?All big bore air cooled yzs make noise,especially the 465 and 490s.Its the cooling fins that cause a lot of racket.The pipe vibrating on the mounts dont help either.Mine always sounds loud and thats after a complete top and bottom end rebuild!