Interesting discussion! I can't speak for Billy's issue, but bringing this topic back made me think about the way I handled the outboard, and indeed makes me wonder if there was operator error in the equation?
I knew to lay it down on the throttle handle, and always did transport it and store/work on of them in this manner. I do RTFL despite the manly urges to do otherwise. Actually, I stored it upright and only really remember laying them down while in the back of the SUV on the way to/from the infamous CLR event (which I am bummed that I can't attend this year!!!).
But!!! My boats have sat in slips the entire time I used both of these motors on either boat. Because of the low coaming on the 16, and the stern rail seats and coaming on the 19, while at dock, the motor is titled with the throttle facing upward. Well, not all the way up, but at a North-Easterly direction so to speak. Meaning, around a 45* angle up.
Hmmm...wonder if this contributed to the fouling? You know, I suspect so as they were oily. I would swap them out while on the water (learned to bring the tool and spare plug!), and would smell gas too, but that's probably fairly normal with the choke on. Seems likely that either the short running time or at-slip tilt angle are the culprits.
What throttle angle are you slip rats using while raised at the dock?
Still, dog gone carbs jam up too fast. This makes me think about something else too. Jet sizes. That is, the carburetor jet sizes. A lot of you guys know this, but to help understand what's going in the carburetor, the carb "main" jet is the small metal part within the carb that draws liquid fuel up from the fuel bowl during operation at some point higher RPM's then idle (when opening the throttle beyond idle. Actually to be more specific, there are two jets, the pilot jet for idle and very low speed operation, and the main jet adds more fuel when the throttle is opened up. Where the two engage with the throttle handle is for a deeper discussion, but suffice to say the pilot jet runs the engine at idle and at small throttle openings, and the main jet then draws more fuel as the throttle is opening by way of increased vacuum. The jets draw raw fuel up into their tiny (sometimes hair-width) openings and the fuel atomized as they leave the jets into larger openings with negative pressure (from the piston pulling air through the intake, then opened valve of the throttle).
Anywho..these jets have sizes like 28, 30, 32, 35, 28, 45, 48 for the pilot jet (talking small but high performance motors like outboards) and main jet sizes ranging from?? Guessing 98--200, depending on the motor. The larger the size, the larger the opening. The EPA has forced less emissions and the manufacturers are making these jets smaller for less unspent fuel emissions. Part of the reason by the economy is so good on the 4strokes--their jets are quite a bit smaller then older 4 stroke motors, and certainly smaller than 2-strokes because 2 strokes by design will need almost twice as much fuel (appx).
Makes me wonder if replacing these jets on the 4 stroke to a little larger size will cut own the crap that will clog them. It would take a larger piece of dirt to clog. It would run richer, and not be quite as efficient, but I bet it would help to keep them clean.
But then there's the vibration. Both of these single cylinder 4-stroke engines seems to rattle the whole the boat and were loud compared to a silky smooth 2-stroke twin (at least our Yamaha 8hp). It can't be just me that noticed how much more vibration the 4-strokes have?
Interesting in your thoughts on at-slip rest angle, jet size increases and vibration?
Sorry for the massive thread drift. Maybe I'll put it on track by posting some pics of the wood engine board for those considering replacement of the plastic one. I was kind buried in epoxy, sawdust and paint during the experience, so I don't have many pictures. It's just 9 layers of 4mm marine ply with thickened West Marine Slow cure epoxy covered in carbon fiber sheet, and marine-grade paint, with inlaid elevator bolts. Super strong and will probably outlast me.