kzryderyahoo wrote: You ran the 120/90 on the stock (2.15) rim?
I've owned my 1977 KZ650-C1 since it was new (more than 43 years). I've run 120/90 V 18 tires for very many years on the stock rim. They work perfectly fine. Be sure to install new tubes every time you install new tires. Ed
