Recently I have purchased a Zodiac and it came with a 2004 Mercury 9.9 two stroke motor. The motor was seating in a garage for over two years so I expected it would need some work. Changed the oil, changed spark plugs, clean the tank and hoses. Removed carburator and took it apart. Soaked in carburator cleaner overnight and blew all orificies with compressed air. Removed reed valve and all was good. Set air mix as per book ( 1 1/2 turn) and played with it back and forth. Checked the ignition timing and all is good. Compression is good too. For some reason the motor has uneven working pattern when idling and once engaged lower rpm is creating a stall and puff of smoke every 5-10 seconds, then return to normal and another stall again and again. Any ideas where is the problem? Below there are two short clips how this motor works. Any input will be greatly appreciated. Thanks to all members.