Dave:

K&B? With four head screws it's a 65, not a 60 or 61.

And there are two versions of the Sportsman 65. Take the prop drive washer off - if you see a brass ring around the crank it's the late version amd will last quite a while. If you don't see the brass ring it has the crank running directly in the cast aluminum of the crankcase, and you'd be well advised to see if you can get the later style. They're interchangeable.

In either case use castor oil fuel. not synthetic.

You can get the needle valve from MECOA, its used on other K&Bs. They may have the crankcase too.

And be careful with the head screws, they will strip easily.

HTH.

Bill.