Which Oil for a 1984 XT600
 

Hi to everyone on this site, I have just brought myself a 1984 XT600 so please have patience with me as I think I will be asking a few questions.

My first one is what oil are people putting in their XT's. I have been advised by my local mechanic I should be putting in 10w/40 as if you put 20w/50 there is a good chance of the Clutch slipping.

I live in Jersey C.I., UK so the weather is not too hot or too cold, so what's everyones verdict on this.

5w40 during winter
10w-50 anytime else.

Both are fullsynthetic and I change around 3500km.

20w50 should be fine aswell, but 10w50 should be better 'cause the oil is a bit thinner when cold, and therefore is easier for the pump to feed = quicker lubrication on cold startup.

My bike is reaching 90.000km on stock engine this weekend.