I have what I consider a strange (at least to me) problem. I bought a refurbished 435. It has been difficult to pull the starter since new. I consider myself to be a strong man, but this little saw kicks my butt. If I remove the spark plug it turns over like it should, so I'm guessing there is nothing wrong with the drive shaft or clutch. I haven't pulled the exhaust yet, but I can't imagine that is the problem. Any ideas?