I know that the 87s are known for the 5 head bolt pattern, and the 88- have 7, but what other changes took place? The majority of ones I see are 87s or 89s. Are they all the same after 87, or is the 90 model the one to have,newer the better notwithstanding.

 

That's 6 bolts, not 5, for the 87 and 7 for the rest...the bolts are bigger also for the 88 and up. Small changes to the piston circlip grooves, molybdenum overlay to the inside surfaces of the piston, longer piston pin, small changes to the counter balancer, reeds and air filter using a screw to hold on the 87 and a clip for the other three years, trany gear ratio changed after the 87, different "a" arms for the newer models.

stormnorm

87 zilla
87 quadsport

 

also they changed from round to square a-arms (or maybe it was the other way around) after like 87 or somethin.

 

Thanks man, that helped a lot