'85 18 hp with no spark !

[Evenrude25]

Hi there, hope anybody will help me ?

I just bought a boat with a Mercury engine - As far as I can find out, it is 18 hp and from 1985. Serial number: 9414006, produced in Belgium.

The previus owner said it has sailed ok, but the last time they went sailing, it ran for about 20 minutes and died !

I checked.... fuel is ok, compression about 120-130 psi, but there is no spark !!!

I think the problem is here !?

Unmounted the flywheel - looks ok underneath.

Does any of you know where I can find a wiring diagram for this motor ? I found some pictures of the parts, but not where the wires should be connected.

The one wire for the stop button has been unscreewed, but where to put it ?

 

[Laddies]

Re: '85 18 hp with no spark !

You didn't say if it's electric stsrt, hope this is what you need.

 

[Evenrude25]

Re: '85 18 hp with no spark !

It is with rope.

I think it is the right picture, thank you very much

 

[Evenrude25]

Re: '85 18 hp with no spark !

Is it possible that you have any ideas on how to test the ignition system ?
How can I check the switch box ?

 

[Laddies]

Re: '85 18 hp with no spark !

Here;s the test for the ign system but there is no tesr for the box you test the resy of the system and that if it's OK you teplace the box.

 

[Evenrude25]

Re: '85 18 hp with no spark !

Damn, you are good
Thanks again

 

[Evenrude25]

Re: '85 18 hp with no spark !

Ok, I done the testing with a ohmmeter and written the values in the attached picture, but I am not sure what it means ?

I think the Ignition stator is beyond good ?
By a closer look I see that the brown/white cable looks as if it has been hot - the insulation does not look good !

 

[Laddies]

Re: '85 18 hp with no spark !

Normally on a 2 cyl engine if the stator or trigger fail where won't be spark on either cyl. as the stator is 2 winding and provide electricity to both cyls, if it fails there in no power to the switch box for either cyl to have spark. The trigger is a single winding with a wire on each end to tell the box when to fire the coils, so if it's failed there is no signal to fire either coil. I would disconnet the 2 lead wires to the coils from the box and switch the output from the box, if the spark changes cyls it's the box and if it stays the same it's the coil. I hope this makes sense to you.

 

[Evenrude25]

Re: '85 18 hp with no spark !

Thanks, yes it does.
But I have no spark on any of the cylinders.

 

[Evenrude25]

Re: '85 18 hp with no spark !

Ups... I mixed up..... When I wrote stator i ment trigger.
I have tried to unmount the wires for the trigger and measured the resistance - But no connection at all.

 

[Laddies]

Re: '85 18 hp with no spark !

Disconnect them at the box.

 

[Evenrude25]

Re: '85 18 hp with no spark !

I have disconnected the wires at the switch box and measured the resistance over the trigger and it does not give any reading on the ohmmeter.

So I suspect the trigger to be out of date.

But how to check that it really is this ? I do not know how it is working. Is it a magnetic contact which closes every time the magnet from the flywheel passes by or does it generate a electric impulse ?

 

[Laddies]

Re: '85 18 hp with no spark !

Read the second section of the test for the trigger if if fails these specs. you should erplace the trigger. The trigger generates AC voltage and can be tested with a DVA.

 

[Evenrude25]

Re: '85 18 hp with no spark !

Yes, it's running again. I changed the trigger and it fired up right away !

But now showing another problem !

I had it running for about 10 minutes in a barrol with fresh water. When I took the motor out, the rest of the water from the leg ran out together with some very black oil !

My first thought was gear oil, but I would mean that if gear oil comes into water it gets milky ?

As far as I know, there isn't any other "oil depots" around this motor - Or ?

Could it be that the previus owner has tried to start the motor alot when drifting a shore, so that ther is fuel oil stuck around in the engine ?

I tried to fire it up again in new water some time later when it has dripped of, but the same result - Some very black oil together with the rest of the water !

Any ideas ?

 

[Laddies]

Re: '85 18 hp with no spark !

Any time you run a 2 cyl in a closed tank at lowspeed the oil residue gathers in rhe mid section and when you pull it out you have a mess.

 

[Evenrude25]

Re: '85 18 hp with no spark !

OK, I just thaught it was some more than I have seen before.

I think I will take it for a ride and see how it goes ;-)

And I want to thank you very much for your help. It is very good to have this forum to ask questions and to have a response. As a non pro it is a very big help. Thank you, and it can not be said to much