Hey dudes. Been reading through all these posts for the past few weeks. Bought a used j16 with a 25hp yamaha mshx3 and it crushed it on the water test before I bought. Idle, 1/4 throttle, 1/2, 3/4 and WOT. Couple days later took it out and was having this issue when I'm coming out of idle and it won't throttle up it'll do this stuttering thing that your reaction is to immediately throttle down. Inspected fuel line and it was pretty nasty, previous owner was running pump gas through her (original owner of skiff and o/b) and it sat for a year (occasional start up on muffs), replace fuel line and all fittings everything clean and snug, cleaned fuel pump and filter, put new plugs in and checked compression, 125 across all three cylinders, unplugged float bowl drain screws and held rag under and shot some carb cleaner inside got some mini pieces of carbon out (can't reach bottom carb without some piece of space age reticulated technology), water tested again and ran like a champion through the whole range of the throttle, but then did the stutter thing after a while and had to idle back to the ramp, did some more rudimentary cleaning out and tested again and had same experience, good running and bad running, except while idling back to ramp I noticed really hot pee (sorry don't know technical name), motor cut out and was hard to start, idled to a nearby dock and let the engine cool off, pulled out of water to see if I picked up a plastic bag or some debris, nothin, idled back to ramp. This is where I stand today. Plan on replacing impeller and thermostat as it won't hurt the motor anyhow, and after some manual readin I read that this model doesn't have an alarm for overheating but does have like a safety mode it goes into if it is overheating and won't throttle past 2000 rpms (I think that's the number) wondering if this stuttering is "safety mode" or another issue. First skiff. First outboard. Been cramming my head with manual reading and forum reading. Would really appreciate any feedback, as I'm on of those broke guys.