200 Merc Knock

I'm buying a boat this weekend with a 96 200 Merc which has been rebuilt. I may be taking on a project. Please let me know what you think.<br /><br />The owner last ran it this summer when it started making an intermetent knocking sound. He returned the boat to its lift and had a Mercury tech take a look at it at the dock. He says that the tech said that one of the carbs in running lean and cleaning/adjusting the carb(s) may fix the problem.<br /><br />After a battery charge, we started the motor yesterday. It started fairly easily. I heard the knock which happened randomly 3-4 times a minute at idle. I did a compresion check and it had 130psi on all 6. I pulled ignition wires one by one as it ran and only heard a drop on the two middle cyls.<br /><br />Could the knock be occuring only because there is no ignition in one or more cylinder, or, is this going to take more time and money?

Re: 200 Merc Knock

I'm guessing here from the description, but I'd think a *mechanical* knock would be more consistant and not only a few times a minute.<br /><br />I'd bet you're looking at carrb or ignition issues. Anyones guess as to what though.<br /><br />-W

Re: 200 Merc Knock

I picked up the boat and dropped it with a good mech. Engine is fine except carbs need a good cleaning. There was more water than oil in the gear case though. Thats were my knock is comming from. May need to replace it. We'll see. It was still a great deal.

Re: 200 Merc Knock

Saw some new ones cheap on "BoatTrader.com"...lower foots that is.....