1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

[jporter5333]

I was putting around at about 1/4 throttle when I took off, the boat didn't seem to run up the rpm's like it should and died pretty quickly. Restart it but it won't run up rpm's in neutral and it dies when I engage the drive. Finally just gets to where it won't even start. Get home and there is no spark to the plugs. Replace plugs and wires still nothing. I have checked the stator and the trigger and they ohm out ok. I also didn't show any voltage to the coils so does that mean it is the switch box?

Another problem I have is when I took the fly wheel off I didn't realize that the fly wheel and the hub were in two pieces. So when I bolted it back up I'm pretty sure I got the fly wheel turned wrong. To fix it I brought the top piston (#1) all the way to the top and assumed that that was tdc. Then I unbolted the fly wheel from the hub and turned so that the zero timing mark on the fly wheel lined up with the index mark. If that's wrong I would appreciate some help with that too.

Thanks

 

[jporter5333]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

By the way, does anyone know where I can get a tach. to plug in to the control box? It is either a 4 or 5 pin connection. I think the prop they put on is a little larger than the other and I want to check it.

 

[jporter5333]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

It also might be helpful to know that this was the first trip out on the new prop and newly rebuilt carb and fuel pump and up until the motor quit it had been running better than it ever had (at least since I've had it).

 

[jporter5333]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

Anybody have any ideas?

 

[rustyh]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

check your coils i got the same motor and have had some of the same problems i pulled mine off and one was cracked , i was still getting spark but very little

 

[jporter5333]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

Thanks for the reply rustyh. I discovered another problem last night, I found out that the switch box is for a 25hp motor. I had decided to change the coils any way just to be safe but now maybe I should change the switch box too?

 

[shankforce]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

If you find it is not the switch box I would get a new stator. I checked mine out fine but it was bad enough to cause the same issue after I changed it problems went away.

 

[jporter5333]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

Thanks for the reply shankforce. I've really been giving a lot of thought to replacing the stator and the trigger while I'm into it and that way, whether they're bad or not I won't have to worry about it anymore because it will all be new. I'm afraid my biggest problem will be after I replace the parts the fly wheel is going to be on wrong (see my first post at the top of the page). If anyone can help me with that, too, I sure would appreciate it.

 

[shankforce]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

You should be good on the flywheel I have done that my self before. As long as you set TDC you should be good.

 

[zekkfett]

Re: 1981 Mercury 40 HP 2 cyl. 2 stroke Serial #5894xxx

I have a #589.... motor too, and I am having trouble finding a fuel pump kit for it. Where did you get yours? Or what is the kit number?