I was just up stalling my 1975 C-150M. It is equipped with a Horton STOL kit, and has the taller rudder of the later 150's (more authority than earlier 150's). During the approach to stall it was not possible to maintain roll control with rudder alone. I reached the rudder stop on each occasion, while the gentle rolloff continued - damped, but not overcome. When allowed to break in the stall under these circumstances (roll within 15 degrees of level, hardly controlled, but lots of yaw), the predictable spin resulted, but had not been deliberately entered.