New boater confused

[stompie]

I have two identical Merc 3cyl 60hp. When I look at the wiring in the motor they are totally different. Wires connected on one are not connected on the other. I presume that even though you have two motors they are still wired up the same. On the startboard motor just to the left of the oil pump there is a little black box with a few wires coming out of it. On the other motor this box is missing. Can anyone tell me what this box is and what it does.

The peehole pipes are also connected differently. One motor has a pipe coming out on top just under the cowling. The other comes out on the port side about halfway down. Is this normal or should I change them all to the same.

Thanks for a great forum. Good advice is hard to find here in South Africa.

 

[tashasdaddy]

Re: New boater confused

appartently you dont have to identical motors, what are the serial numbers on them. mercs exteriors can look identical for several years, but different inside. do they both run?

 

[stompie]

Re: New boater confused

Serial numbers are very close together and when I checked they are both 1993 models. The one motor starts first time, idles like a dream but doesn't rev up good. I pulled the middle plug lead today an it stalled. I adjusted idling and tried again and motor stayed running. I think it has only being running on two cylinders. Pee stream not as strong as other one.

The other motor is harder to start, idle rough but revs up to 4300 no problem. This one however tends to cut out for the first 5 minutes or so as you put it into gear.

I have booked the boat in to have the carbs rebuilt and impellors changed.
Will do compression check this weekend.

 

[tashasdaddy]

Re: New boater confused

your own the right track. do not rev the engine in neutral above 1500 rpms, can cause a runaway engine, you can shut down, until it runs out of gas. can cause major damage.

 

[stompie]

Re: New boater confused

Last time I was at the shop I asked them to check tach not working. They got a new one and connected it up, also didn't work. They told me I need a new stator. Can there be another reason for tach not working? if stator is bad then surely battery won't charge. Have done about 20 hours since and battery charge is good and motor starts on the turn. Perhaps it could be my initial wiring concern. I am not sure if it ever worked.

I am thinking of swapping the tach's around as the other one works like a dream, in order to eliminate the tach itself.

Where is the rectifier/regulator? What does it do? and what does it look like?

 

[tashasdaddy]

Re: New boater confused

the engine would not run if the stator was bad, the rectifier, converts the AC electricity, produced by the stator, to DC electricity to charge the battery and run accessories, the pulse for the tach comes off the rectifier,also. you need to take the serial numbers and go to mercurypartsexpress.com they have engine diagrams.

 

[stompie]

Re: New boater confused

Thanks for the advice. Will visit the site. Outboard parts are very expensive in South Africa as all are imported and our currency isn't the strongest in the world, so i'm hoping there is no major problem.

 

[stompie]

Re: New boater confused

Visited the but unfortunately my serial nos aren't recognised. They are obviously European as boat is South African. S/Ns are 09765057 and 09765058. Are there any other sites with diagrams or should I try and locate a manual at a library?

 

[stompie]

Re: New boater confused

Sorted tach out this weekend. Finally got a multimeter checked charging and all ok. Checked wiring in loom from regulator to tach and found no continuity. Ran my own wire from regulator to tach and it worked. What a cheap solution to a possibly expensive problem.