Spike, Thanks for your comments. I believe the motor is a 1967 and for this reason I am running a 50:1 mix. I hope this is correct and not the cause of my seizing. Are you familiar enough with this motor to tell me where on the back of the engine the thermostate is. I may pull the thermostate out,,,, as a temporary means of determining the issue,,,, and see if it solves the seizing. I completely agree with your comments on seizing not being good on an engine. I just hope I have gotten by with it this once.