i have a question.i own an 82 sporty and thinking about changing the drive sprocket from a 21 tooth to a 23 tooth.the question is will i have to modify the sprocket cover?is the sprocket the same size as the original or is it larger in diameter?with the stock sprocket it looks real close to top mount bolt mount any info will help thanks

pops

 

The 23T is a larger OD than a 21T, but it should fit OK.
On an older bike the 23T fits without any alteration to the cover required.
On a 1982 there may be a small amount of grinding needed.
I am sure someone who has a 1982 machine with a 23T will chime in here with how it works for them.
pg

 

If you run an o-ring chain you will have to grind a little off for sure. I did this on my 1980. Here is a [blurry, sorry!] pic. The grind on the standoff is what i needed; the one at the top was done by an improperly adjusted chain.

 

ok thanx mick and piniongear i was lookin at my vin#'s foundout its an early 82 dont know if that makes a difference on that cover design

 

I have an '83, and I had to grind the inside cover bosses a little to get the 23 to fit, as it's a little larger diameter than the stock 21. Nothing drastic, though. I don't run an o-ring chain - if you do, you may have do grind a little more than I did to get adequate clearance.