Dan
If I run my 9.8 2-cycle hard on a plane for awhile, so it heats up well, and then stop the engine for a little bit, like to talk to someone, then when I start it back up it will often stall at low speeds and have no punch at high throttle. After a nice rest, it comes back to normal. One thing that seems to help is if I take out the jet adjustment screw and spray in WD-40. My 9.8 is 10 years old, but it has done this for 8 or those years or more. I had it into a Tohatsu shop and they ran it hard over and over and could never replicate the problem.

Paul L