Mariner 175 HP Ignition Problem

Limex

Recruit
Joined
Dec 28, 2003
Messages
3
Initial Problem:
1) We took the boat to the lake, run about for 10 minutes. Then one or 2 of the cylinders dies, the engine lost power and the boat slow down to just above idling speed.
2) We turn off the engine. Check the engine to see what's wrong. I see gas and abit of smoke comes out of the middle caburators. The engine was able to start again, and run at about 1/4 of its max power even when we push it to wide open throttle.

3) Engine ran like that for 5 mins, then the dead engine kicked in for about 20 seconds and drop out again. When getting close to shore, we put engine into neutral, it dies, and can't be started again.

We did a few diagnostics:
1) We check for spark on every single spark plug.
Results: There are sparks on the 2,4,6(port side) but none present in the 1,3,5 (starboard side) The sparks makes by the spark plugs 2,4,6 are small blue, which seem to be insufficient by the manual desccription (SELOC Mariner Outboard Repair)

2) We swap ignigtion coils between 2 and 1.
Results: The coil from the cylinder 2, that was working, when connect and use for cylinder one, no spark produced. The coil from the cylinder 1, that was not working, when move to cylinder, sparks produced. So coils reuled out as the casue.

Question: Which should I check next?

1) I will be looking at connections in the switch box
Anyhting I should pay attention to?
Are there any fuses to check for?

2) I will open up the flywheel and check the stator. Mabe this is the casue too
Any area I should pay attention to for wear and tear that's not obvious?

Thanks for viewing,
Liem H
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Mariner 175 HP Ignition Problem

Welcome to iboats. :)

Yer gonna need a manual. It's either the stator is no longer sending power to that switchbox, or the switchbox is getting it and not processing it. They're both expensive parts, so you don't want to guess. You can test the stator with an ohmmeter. A manual will help with that process. Or you can try swapping switchboxes. If the other cylinders fire, then it's the switchbox. If it's the stator, the same cylinders will still fire.
 

Limex

Recruit
Joined
Dec 28, 2003
Messages
3
Re: Mariner 175 HP Ignition Problem

Mucho Gracias, will post results
 
Top