Mercury 50 no spark.

[jwatson]

So I changed the impeller on my merc 50 yesterday, started it up on muffs and it ran fine for 60 seconds then died instantly and I've not been able to start it since.
The spark looks weak to me. I checked the kill switch and it was intermittently faulty so I have removed that (it's a make to kill system). Still nothing. I've tried easy start ( I know I shouldn't) and still nothing. Any help appreciated.

[A1an]

Check the earths on the switch box and the earths on the back of the coils (iirc there are strands of earth wire on the back of the coils on that engine), they corrode up something hellish.

Also check the wiring for its integrity, the loom on those engines goes like shortbread, they crumble away to nothing.

[jwatson]

Ok thanks. Are the coils on the side of the block or under the flywheel? Ta

[A1an]

Side of the block

[jwatson]

Ok will check. Although there is no spark on any cyl. Very small chance of them all dying at once is there not?

[A1an]

Thatl teach me to skim read.

No, very unlikely but check the switch box earth, seen it before.

[jwatson]

Am I right in thinking the earth wire is the black one which I have removed the cap from?

[jwatson]

Ok thanks. Does anyone know if the picture I showed is indeed the switch box earth I need to check? Ta

[bartiny]

Originally Posted by jwatson

Am I right in thinking the earth wire is the black one which I have removed the cap from? Attachment 97788

It is not easy to make out with that picture, and I am not too familiar with that engine, but if it is a black wire attached to the block then it is an earth.

If it were me I would be checking all earth wires that I could find, and any other connections just to be sure they are clean with no corrosion.

Sorry I can not be of more assistance.