Just bought a (first) boat - it has a 1975 Mercury 850 (85hp), 4cyl, 2-stroke motor on it.

The previous owner told me that the first time you start, it can take a bit, but then it runs great thereafter. That's completely true, however when we took it to the lake, I probably cranked (intermittently) for 15 minutes before it finally started. I felt that was a bit excessive, and am looking for ideas to improve starting performance.

It has a new CDI electronic ignition module in it, new plugs, good compression, and like I said, restarts good after the initial start.

The only other thing that I can say is that our first outing, we never could get it to plane out. I'm a noob, so it's entirely possible that I wasn't trimming it correctly or something, but the engine churned and churned, and the GPS never registered much over 8mph.

Wellcome to the boating world. Thats just the nature of the older motors.Just be sure you have the primer ball pumped up hard and a good hot battery.

I just had my 650 repaired for doing the same thing. The choke needs to be working properly. First check to make sure that when you press the choke button that the choke actually works and second is to have the choke butterfly adjusted so it closes properly. Mine went from a long hard start to starting with in two seconds just by getting this fixed. Good Luck to you.

Hmm.. I just tore my throttle control down this afternoon and cleaned up the electric choke switch - it had been totally corroded and in-op for some time.

I had tried the manual choke numerous times, and had never really noticed it helping much. I'll try to check the butterfly. Do you know, is is supposed to close off completely?

Also, do you find that lifting the throttle lever when starting makes any difference? It seems like mine has always wound up starting in the idle position.