90hp Merc 1979 Inline 6

[Fishin4fun]

Ok, I finally got the motor installed. I have a few questions though,<br /><br />1. If I turn the motor, fairly quickly from one side to the other, it will stall. I have checked all my connections and everything is good and tight. I ran her on the lake WOT and no problem as long as I dont turn quick, at idle if I turn quick (docking maneuvors) it will stall.<br /><br />2. Are there any adaptors to convert the mid-80's control boxes to the 79 model that I have with the plug on the side of the motor? I would like to buy a newer contol box and replace my throttle cables as the box/cables now are a little stiff, also I would like a control box that locks into neutral, which mine does not.<br /><br />3. The motor is equipped with power tilt/trim and it works great, is there a way to install a trim indicator?<br /><br />4. Would running 16oz in 5 gallons pose any problems for my motor?<br /><br />Thanks,<br />Ed

 

[JoeW]

Re: 90hp Merc 1979 Inline 6

If this is an outboard, check your fuel line as you turn the motor. It could be getting pinched.<br />Just a thought.

 

[Fishin4fun]

Re: 90hp Merc 1979 Inline 6

That was my first thought, but unforturnately not the problem, any other ideas out there?

 

[DJ]

Re: 90hp Merc 1979 Inline 6

Fishin4fun,<br /><br />Those plugs that go to the side of the engine are notorious for causing problems.<br /><br />If it were me, I would hard wire it.

 

[Mercury140-I6]

Re: 90hp Merc 1979 Inline 6

Hello:<br /><br />I had something like that happen about 3 years ago. One of the pins in the side connector, Motor side broke and I had to have the engine turned at just the right angle to get it to start. Take the plug off the side of the motor and look in the female end to see it one of the plugs are still in it, if not check the pins in the male end to see if any are loose. The internal wire harness is not that expensive and easy to get. I have the same year motor and have a Quicksilver 3000 control box for it. the mechanic just took the existing wire harness and put into the new controls. Works great, trim and tilt on the shift/throttle lever.<br /><br />Hope this helps.<br /><br />Craig

 

[jayboy67]

Re: 90hp Merc 1979 Inline 6

I've had a lot of problems with my 1976 Merc 850 cable to the side of the engine. Mine was it wouldn't start unless you turned the engine to a certain position. I guess it was "making" a broken connection close. When I got into the throttle console and the wiring to the plug I found that several of the wire's insulation was crumbling. I slit open the cable behind the motor plug and did some splicing and insulating and got it all working again. Seems only the wire close to the ends were in that condition. My boat has spent 99% of it's life in open storage with just a boat cover protecting it. My local Merc Dealer said there was no way he could find a cable to replace it. He is the same one that hard wired one wire when this problem first started appearing. His fix only worked for a short time so I don't think he correctly isolated the problem.I think that it worked for awhile just because all of the handling of the cable it made the connection for awhile. <br /><br />I'd open the throttle control box and check the condition of the insulation. If crumbling there then it will be up in the cable too. Not sure how your switch kills the magneto but I think they all short it out like on an airplane.

 

[Chris1956]

Re: 90hp Merc 1979 Inline 6

Fishing4Fun, I have had the same problem on my '77 Merc 150HP. It had a broken wire in the molded rubber plug. Most positions it worked OK. I cut it open and used a butt connector to repair. So far, so good. You could replace it with a new or used harness. Probably both are available on the internet. You could do a google search on the Merc part number

 

[Mercury140-I6]

Re: 90hp Merc 1979 Inline 6

There is one on E-Bay right now. Search for "Mercury Outboards"