l008com
New member
I've got a 1989 Mercury 90 HP, its a 3 cylinder, 2 cycle motor.
This past summer, I was out for a ride when it started to lose power. It was sporadic over the course of a couple of minutes. It would come on and off, on and off. Then it died. I was unable to restart it. I tried until the battery started to get week. Then I had to plan B it and do some crazy heroics to recovery the boat.
A few days later, safe and sound in my driveway, I tried to figure out what was going on. I removed the plugs and confirmed there was fuel. Then I used a spark plug tester and confirmed that NONE of the 3 cylinders were getting spark. That seems odd to me, given that all three plugs each have their own ignition coil. What would kill them all, all at once.
One thing that was suggested was maybe the kill switch. Or the man overboard switch. In 40ish years of owning this boat, we've never used that. I honestly don't even know how to use it. But I know its in the same position its always been in. Is there something else I should do or some other way I should check it?
And if its not that - which I tend to doubt - then what else could cause no spark like this?
Unfortunately I had a busy Summer and haven't had time to dig in to this until now, but those carbs are full of now-old fuel and I really at the very least, need to get this thing running so I can winterize it and pack it away.
This past summer, I was out for a ride when it started to lose power. It was sporadic over the course of a couple of minutes. It would come on and off, on and off. Then it died. I was unable to restart it. I tried until the battery started to get week. Then I had to plan B it and do some crazy heroics to recovery the boat.
A few days later, safe and sound in my driveway, I tried to figure out what was going on. I removed the plugs and confirmed there was fuel. Then I used a spark plug tester and confirmed that NONE of the 3 cylinders were getting spark. That seems odd to me, given that all three plugs each have their own ignition coil. What would kill them all, all at once.
One thing that was suggested was maybe the kill switch. Or the man overboard switch. In 40ish years of owning this boat, we've never used that. I honestly don't even know how to use it. But I know its in the same position its always been in. Is there something else I should do or some other way I should check it?
And if its not that - which I tend to doubt - then what else could cause no spark like this?
Unfortunately I had a busy Summer and haven't had time to dig in to this until now, but those carbs are full of now-old fuel and I really at the very least, need to get this thing running so I can winterize it and pack it away.
