Replacing rear sprocket.. need advise

[ksizzle]

After riding this weekend my aluminum rear sprocket wore considerably and needs to be replaced. The bottom chain guide was at a slight angle putting pressure against the chain and then onto the soft sprocket. So now I need a new one. I know the rule to switch all three at the same time, but since the rear got worn out in a day from my problem is it still necessary to change all three? I can go count the chain but does anybody know off hand what a +4 swingarm takes? I have an 87 with a 13/40 setup and will probably switch to 42t steel in the rear now. And also any suggestions where to get these; just the rear or a whole kit?

[bansheesrtoys]

well if all 3 were new and the rear wore out in a day because of a problem, then you could get away with just replaceing the rear, but if you plan on going two teeth up in the rear more than likily the chain will not be long enough. i don't know how long as i have a -2 swing-arm, but what ever chain size you have now just add about 6 more links and cut it to size when you get it.