Well that sucked. So, long story short, got to the river, put the boat in the water, engine craps out. Back to Anchorage.
Long version: Driving up to the river and one of the guys here calls me on the phone and, during the discussion, strongly advises me that it is very necessary to have a motor lift on my Sport Boat and not use the factory transom on this river. I need about inches of lift. OK. There was a town up ahead with a small hardware store. I bought a 2x10 scrap 16" long and two of the biggest c clamps in the store. Now, I am deliberately not naming said forum member becuase I don't want anyone here, most of all him, to think I'm laying blame for what happens next. I'm not. And he has taken time to give me tons of great advice and input on a whole range of outdoor topics. This advice was well intentioned.
BUT, when I got to the river and hung the outboard on my makeshift lift, I noticed the pick up ports for the water pump were completely out of the water...with the boat loaded. I lowered the "lift." Still out of the water. Sit my fat but in the boat and that pushes them down int he water. Great. So I start off on the river checking things out to see if I can go upstream before I head off downstream to hunt, which was always my plan anyway. I had to hit max throttle to make headway. That got me 6.6 mph on the GPS. Slow but it works. HOWEVER, with the throttle wide open, the water coming off the stern is going way around the lower unit, and the water pump pick ups are dry again. Crap. SO I back off the throttle and the water pump starts pumping water again. But now I can't make head way against the current. I'm 50 yards away from the ramp and floating away, so I bite the bullet and gun it and head straight for the bank, knowing I'm running the water pump dry.
Back to shore, I pull the "lift" (i.e. the plank and clamps) completely off the boat and put the engine back o the factory transom. Start it up and it idles good and pumps water. (Which surprised me.) Back into the current and head up river again. Agai, it takes wide open throttle to make about 6 mph, but the lower unit is fully submerged and the water pump is pumping. (Not as much as I would like, but pumping.) Then the engine starts misfiring and thumping the hull of the boat about every half second. Back off the throttle and it goes away, but I start drifting down stream again. Back to wide open throttle and it starts missing and thumping again. It still makes power and I can still make headway at WOT, but at 6 mph, I know I'm going to need continuous WOT for about 5 hours to get back to the ramp. I'll have to make two runs if I get a moose. I also promised the girlfriend I wouldn't take any risks out there on my own. Soooooo....back to the ramp and on the trailer for the drive home. (By the way, while I was loading it on the trailer, and entire spruce tree, roots and all, floated down, crossways the river, and just missed my boat by a foot or two.)
So, I know I'm buying a new water pump for certain. The other issues...I don't know if they are connected to running it with no water in the water pump or not. It's a 40 year-old outboard; this could just be some other maintenance issue rearing its head. At the moment, I don't know. (It ran good all summer. Until the water pump puked and the lower unit oil seal puked.)
Lastly, just to reiterate, I don't want said forum member who said "put a lift on," or anyone else, to think I'm laying blame or like I wished I hadn't listened. It's my boat, my engine. I'm the operator. I'm responsible for making sure the lower unit is deep enough in the water to feed the pump. I didn't do that.