l have a 1974 Honda MT250 Elsinore, and it does 6,000 RPM at 60 MPH.

What is the gear ratio of the gear you would be in? Also, what are the sizes of the two sprockets?

Ca not give you an exact amount without knowing those numbers. l can tell you your RPM would go up. Not by much though, maybe 100 or so.

Rear sprocket bigger = engine turns faster. dive 4 by the number of teeth on the old sprocket, multiply by 100 and you have the %age increase in your engine rpm.

l thought you would want the back sprocket smaller to lower the revvs at a high speed
by the way steve y that little equation bout divide by 4 x 100 very handy thing to know

Bigger rear sprocket reduces top speed, increases take off. Most guys who like to wheelie, get the bigger rear sprocket so the bike will pop up easier.