It's, of course, hard to say. New rebuilds sometimes run hot. Timing will cause it. Carb has no bearing really. I would like to know if anything has changed, fan distance wise, during rebuild. What did change? Was the same motor in there and was rebuilt or another motor was in there? If the engine is "new to you", I guess it's a different engine than you had before? A proper shroud will help. Is your T-Stat 160 or 180 or? Is it new? Is it working? Top rad hose not collapsing?
