Loss of power on 71 50 Hp Evinrude

Good morning guys. I am having a loss of power on the top end of my 71 50hp Evinrude, model 50173S. The motor starts good hot or cold. Idle and low speed operation is good. I began noticing the power loss towards the end of last boating season (we are in North Dakota). With just myself in the boat it would get up and plane but seemed a little slower than normal. With a second person on board it seemed a bit slower yet. Put a third person or more in the mix and she was just plowing water, seemingly lacking the power to try and get up. The motor sounds like it's really trying but not gaining the RPM's to get there. The kids wanting to go tubing and it really laid an egg on that one, just struggling the whole time. Then last weekend we had been out fishing, motor ran fine other than high end power loss and on the return trip to shore I started motor, let warm up a while and cracked the throttle. Motor barely moved the boat sounding like a sick cow. I thought ok so I'm on one cylinder now. We idled into shore and I had my son drive the truck to the boat ramp and I began limping over to it. I wasn't sure if I should continue trying at WOT but gave it a try. About half way to the ramp it began doing a quick lurch here and there and all of the sudden it hit both cylinders and I was up and running, but still without peaking out at my top end RPM's. I realize it's only a 50 horse but this motor used to get up and pull two water skiers no problem and currently won't hardly pull a seven year old on a tube!

This spring carb kits were installed and a good cleaning done on both. Fuel pump was new last season. Spark jumps a 7/16 gap and compression is 120 on both cylinders. I tried squeezing the primer ball when WOT on the lake with no change. I talked to the local boat mechanic and the ignition system was brought up suggestion maybe a coil pack is causing this lack of power showing good spark in open air but maybe is just weak enough in the cylinder for a lack of top end RPM's, or that the power pack is dropping a cylinder at times. Any ideas or suggestions anyone might have is greatly appreciated. Thank you!

Run with the cover off.----------Try running with a timing light to see if spark is an issue.

Sorry I've taken so long to post any test results! Been on call for work and unable to leave town until today. I ran into the marine mechanic and with talking to him he mentioned ohming the coil packs and gave some rough numbers on what primary and secondary should be and upon checking was getting some inconsistant readings on one of the coils. I pulled both coils off to inspect and found the particular pack that was giving variable readings had cracks in the coating with two being pretty good sized. I ordered two new coil packs and also a new power pack since I believe the old one was a good fifteen or so years old. Going to go for a test run to lake later today so hopefully will have positive results to post! If that doesn't cure the issue will try with cover off as Racerone suggested and see what happens.

One thing I failed to mention that really makes me curious is since I've noticed the power loss the spark plugs, mainly the top cylinder, are always wet with fuel. Doesn't matter if I've been running WOT for a long duration or not. Always wet. I asked the mechanic about it and he claimed on older two strokes you never really burn all the fuel away so you'll always have residual on the plug. Doesn't sound right to me at all. Makes me think it is a spark issue and I'm not hitting that cylinder to effectively burn the fuel. Any thoughts?

So my spark issue is solved. But now I came across a fuel suction issue. The fitting on the motor housing that couples with the fuel line from the tank began leaking. Upon start up the primer ball would firm up nicely but soften after ignition. After narrowing down the leak and replacing all fuel line and fittings for good measure it became apparent I needed a small adjustment on the S/S idle. Here raised a question for me. I've read in a few other posts with joereeves the procedure for setting the S/S but my question is when setting these should the motor be in gear? The marine mechanic around here has always told me to be in gear. But when I've read some of the posts on hear I don't see anything about being in gear. Any clarification on this would be very helpful, thank you!