Hello, I own an '84 XT 600, and I heard this model may have had a problem with rim cracks, is this true?

Also, which oil is the best to use. The bike has clocked 48000 klms, but was rebuilt at 45000. I have done two oil changes since, the first at 46000, and the second at 47000 after the run in period, (replacing the oil filter both times) using Castrol TT oil. The bike is used mainly as transport to work, with at least one highway run per week. I'd appreciate any advice.

'...may have had a problem with rim cracks, is this true? '
yes, sometimes. if you notice cracks, change the rims against the ones of an '85 model (55W). they have the new type of rims.

'Also, which oil is the best to use...'
you should use a good quality MOTORCYCLE oil because in your bike the oil has to do more jobs than in a car engine (clutch, gearbox).
the brand is not so important, but the API-specification is. SE is low quality, SG is high quality oil.
if you ride more in high temperature conditions a xW50 should be prefered, else a 10Wx.
i don't want to start a discussion here about mineral or synthetic oil. in my opinion mineral oil is good enough if you use your bike 'normal'.
but whatever type and quality of oil you choose, the most important of all is:
-carefully warm up the engine, ride at least 20 km until you use higher revs (<4500)
-perform regular oil change every 5-6000 km
-keep the oil level always at maximum

and a very useful modification would be to mount an oil thermostat (if the bike is equipped with an oil cooler). this helps to warm up the engine more quickly.

regards
klaus

Thanks Klaus. Been all over the rims with a fine tooth comb...polished the spokes while I was at it!