RE: picco 40
Picco always made pretty good engines...
Ive had the Picco 40 and 60 engines .... some year back. Good running, and reliable. And for a while there they were very inexpensive, compaired to Rossi or YS at the time.
Forget running it with a muffler...... not worth the hassle... the engines are pipe timed..... definately need a good pipe system to perform at their best.
of interest... you may be familiar with OPS engines... Picco is the "P" in there. The engines are very similar in design to the OPS pattern and marine engines.
picco mainly focuses on marine and car engines now ... high rpm applications.