I have a 13.5 HP I/C OHV briggs and stratton engine in a riding mower i picked up last week. It's running well enough but it needed some tuning in the carb. From what I can find, it had two screws for adjustment. The mixture screw had a cap limiter attached which I took off but it's still hard to adjust.

I was wondering if anyone knows where I can find a good service manual or repair manual for this engine. The model number is 21B80 70296 E1