which muffler fits a honda XL250R???

[blablau]

hi, i have a 84' honda XL250R and need to replace the exhaust,
does anyone now which other model (350,500,600,+XR,.....)muffler will fit.
headerpipe looks o.k. ....
where could i get something whitout spending too much money?????
and my other problem is,it's from 84 so does it needs valve lead replacment stuff or not, drove already 7000 km in the last half year with just unleaded petrol, makes a littel noise in the top end,but i was thinking its normal (hard to know with all that because i always used to ride 2 Strokes......)
and how can i find out if they did something to the engine???
i really like this bike,but would get hardly the money for a engin rebuilt together......
drives well,heaps of fun!!!!
thanks for your help!!!!
cheers

[djadams]

No idea about which other mufflers might fit I'm afraid, but it almost certainly won't need lead substitute. So long as the head is aluminium, it'll have hardened valve seat inserts as standard (Aluminium heads need them even with leaded fuel).