New member with questions

I am new to this site,and like what I see.It seems to be full of good info.
I am also new to the xj bikes.I am however,an expierienced rider and fairly decent wrench.I had to be to keep my first bike running,it was an old iron head sportster.
I bought an old 81 650 maxim this last may,for the unbelievable price of 500 bucks.I figured since the guy had installed a new battery,starter,plugs,and changed the oil it was worth the five hundred.when I got it,it would start with full choke.The guy I got it from said he couldnt make it run right,and had just had the carbs rebuilt.I took it home pulled the carbs and cleaned them and have been riding it all summer.It had 5400 miles on it when I bought it,it now has 22,300.
I have been researching these bikes and what I've been finding is at between 20 and 30 thousand they start having valve trouble and timing chain tensioner trouble.My bike is still running perfect,and I have not done anything other than oil and filter changes.
Has anyone had problems with a timing chain tensioner and at how many miles.How often does this problem occure?I know I should check the valves,does anyone know the specs on them?Are there any other problems with them I should be aware of?
replies would be appriciated.

 

Check valve clearance every 6 mts or 6000mls
" cam chain tention " 3 mths or 3000 mls
INLET 0.11 - 0.15 MM
EXHAUST 0.16 - 0.20 MM

 

Thank you wizzard.I'll adjust accordingly.

 

Thank you wizzard.I'll adjust accordingly.

 

WOW 2.4K miles per month. When do you sleep?
Best I ever did was 18K in 18 months.

Have you heard of the "Iron Butt?"
http://www.ironbutt.com/about/default.cfm

ab

 

Yeah,its a lot of riding.But when you ride 100 miles or more a day to work and back and then do your weekend riding,its not all that hard to put miles on one and I did buy it to ride,its not a weekend warrior or trailer queen.