1999 25 HP starting troubles

[force314]

I have a 1999 Johnson 25 hp, 3 cyl. on my 20' pontoon. The problem I have is that the boat only gets used on the weekends and sometimes not for two weeks. When I try to start it, I was told by the marina mechanic that rebuilt the carbs, to turn the key on, pump it 4-5 time (priming the motor) then start it. When and if it starts, it blows out smoke and releases raw fuel and oil into the lake. Once it gets running, it runs fine. I was told these motors were a lemon design of OMC and many have had lube pump problems. My mechanic says he could try to replace the pump for $400-$500 or I could just disconnect and bypass the oil mixing pump and run premix. I'm getting ready to put it in the lake for the summer and would like to fix the problem first. Any answers or suggestion?
Thanks.