I changed the oil in my kids lt80 its a 1987 i used 10w40 motor oil the stuff that came out was real thick so i changed the oil removed the small plug and filled the oil till it started to come out the side hole that i removed the bolt from just like the manual said to do.

now when the bikes sitting at idle i hear a clicking coming from somewhere around the rear clutch area any one have any ideas?

 

is that 2 stroke oil?

 

no lol i changed the transmission oil with 10w40 i use yamalube 2s in the injector

 

I have not owned an LT in years, but my recollection is that the manual called for 10W30 oil.

 

If the machine is sitting still and making the noise, it shouldn't have anything to do with the gearbox.
I suggest clutch maintenence to investigate the noise.