2000 115 Saltwater Series issues

[AWC360]

Recently I've been experiencing more exhaust than normal, even after engine has warmup up. When idling, the motor will gradually rev from normal to higher, then a plume of smoke will come out and the revs start low again.

2nd issue: I've noticed water hasn't been coming out of the pee hole very consistently. Could this be a water pump issue or possible debris in the line?

This boat just recently came to my possession. What's the best way to approach these issues?

 

[25xs]

Does this sound like your symptom accurately?

Does this sound like your symptom accurately?

If you post your engine serial number, many here can be more specific on engine advice...

Your engine sounds like an idle circuit (fuel flow for idle only inside the carburetor) is plugged and as it leans out, the engine rpm rises until it backfires ("lean spit") like a sneeze then idles down again...? Does that sound like what you observe? The puff of smoke is from the crankcase backfire clearing out unburned oil. If this is the case, a good carburetor cleaning, using the complete Mercury carb kit, and maybe new floats would fix your problem. There is ALOT of fuel line under the cowling of your engine. When I fix them, I generally replace all that fuel line as well. In 2000 Mercury used fuel lines with a thin, clear liner. Over time, that liner breaks down and sheds tiny shards of plastic liner through the fuel system where the fuel filter does no good. The oil recirculation lines & check valves should be checked and/or replaced at the same time.

Of course, all this is precluded with an accurate cylinder compression test to be sure the engine interals are healthy.