1989 50 hp mer no spark

[joe_dirt]

i,m working on a 1989 50hp mer 4 cylinder the top two cylinder 1&2 have spark but 3&4 don,t have spark, they each have there own coil pack for each cylinders.
i can,t see two coils going bad at the same time so what else should i look at?
and i need to know how to set up the cables and idle because it shifts hard in to gears

thanks

 

[zorak]

Re: 1989 50 hp mer no spark

I am currently having the same issue.you will need to get a multimeter and either build or buy a DVA adapter.I would suspect that the trigger or the switchbox is bad but what you don't want to do is start throwing parts at it. Do a search on this forum and you will find a testing procedure

 

[Laddies]

Re: 1989 50 hp mer no spark

First swap the red and red/white and the blue with the blue /white wires on the switch box, if the spark changes cyls it's the stator. Didn't change put the wires back where they were and swap the trigger wires on the box violet to brown and white to black/white, if the spark changes cyls the trigger is bad, if it stays the same the box is bad. This method takes a while but if you don't have the proper test equipment it will work.

 

[SeaKaye12]

Re: 1989 50 hp mer no spark

Laddies; will that test work on most/all of the older 4/6 cylinder Merc engines?

Specifically; mine is a 1977 850 (no distributor...)

If it will work on mine I will save it for future reference...

Thanks, Chuck

 

[Laddies]

Re: 1989 50 hp mer no spark

Any 4 cyl without a distributor and before CDM