bostonpilot
Cadet
- Joined
- Nov 22, 2007
- Messages
- 23
Hi All,
I think I know the answer to this problem, but thought I'd run it by the group to get some second opinions (read=cheaper) on the problem.
I have a 15hp Mariner (1989/OAxxx series).
Symptom: Good spark on top cylinder with no, or occasional very weak, spark on the bottom cylinder.
What I did-
1 -confirmed symptom with a spark tester
2 - Inspected plugs, wires and boots - looked fine
3 - Using an ohm meter, checked the resistances of the stator, trigger and coils - All I had was a crappy, old analog meter as my good digital one wasn't with me, but the values measured were in "the ballpark" to what the Seloc manual listed.
4 - Swapped the leads from the switch box to the coils and restested with the spark tester - the problem reversed, i.e. the spark followed the swapped lead, causing the other coil/plug to fire
It seems to me that because of the design of the system that the only elements that could cause the failure of a single cylinder are the switch box and the coil/wire/boot. It is my understanding that failure of the stator or the trigger would casue a complete failure of both cylinders. Or, am I missing a failure mode that would knock out just one?
Since switching the lead from the switch box to the coil resulted in the other plug firing, it sounds like the only possible broken element is the switch box.
So, before I invest the $150+ in a new switch box, does anyone have a good suggestion of other possible failures, as well as any other ways to confirm the diagnosis??
Thanks!
I think I know the answer to this problem, but thought I'd run it by the group to get some second opinions (read=cheaper) on the problem.
I have a 15hp Mariner (1989/OAxxx series).
Symptom: Good spark on top cylinder with no, or occasional very weak, spark on the bottom cylinder.
What I did-
1 -confirmed symptom with a spark tester
2 - Inspected plugs, wires and boots - looked fine
3 - Using an ohm meter, checked the resistances of the stator, trigger and coils - All I had was a crappy, old analog meter as my good digital one wasn't with me, but the values measured were in "the ballpark" to what the Seloc manual listed.
4 - Swapped the leads from the switch box to the coils and restested with the spark tester - the problem reversed, i.e. the spark followed the swapped lead, causing the other coil/plug to fire
It seems to me that because of the design of the system that the only elements that could cause the failure of a single cylinder are the switch box and the coil/wire/boot. It is my understanding that failure of the stator or the trigger would casue a complete failure of both cylinders. Or, am I missing a failure mode that would knock out just one?
Since switching the lead from the switch box to the coil resulted in the other plug firing, it sounds like the only possible broken element is the switch box.
So, before I invest the $150+ in a new switch box, does anyone have a good suggestion of other possible failures, as well as any other ways to confirm the diagnosis??
Thanks!
