Update
I pulled the intake manifold and then cleaned out the vapor separator and replace the filter in the separator and also in the water separator. I also replaced the spark plugs and replaced the gas hose between the tank outlet and the 'T' where the fuel line splits for both motors. It took quite a while to get this done (not much spare time) and I also cleaned out the jets of the 9.9hp motor's carb. Last Sunday we had a warm day, so I pulled it out into the driveway and tested the motors. After I squeezed the gas bulb for the 115 what felt like a hundred times, and finally the VST was filled. I turned the key on and off a couple of times, and then the 115 started instantly and idled. However when I put it in gear and revved it up, it got rough and sometimes died when I returned to idle. I pulled one fuel injector lead at a time and I had 3 that were relatively equal and had very little effect when I pulled a connector. When I pulled #4 fuel injector lead, the motor almost died. #4 was way stronger than the others, so it appeared that I had 3 partially clogged injectors. Mills, you were right, fuel injectors are cheap on Ebay, so I purchased 4 and installed them. I haven't test run it yet. I've also replaced the trim angle rheostat so now Mark can see how his boat is trimmed without turning his head around. I'm not sure that I'd spend the $160 for the new rheostat or not, but he wanted it working. I can't bring the motor all the way down because it hits the roller on the trailer, so I'll have to fine tune this when I get it in the water or rig up a way to slide the boat back on the trailer.
When I went to start the 9.9 there was a fuel leak out of the bottom of the carb from what looks like an accelerator pump. I've got a new diaphram ordered.
With all the rain we've had, the lakes are almost all the way back up to normal pool, so in the next couple of weeks I should get to test it properly.