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Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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I have a 2005 Mercury 60hp EFI bigfoot motor. Issue is that

Customer Question

I have a 2005 Mercury 60hp EFI bigfoot motor. Issue is that after WOT it appears cylinder #2 shuts down after about 30 minutes. I have done the following: swapped out the injector still #2 fails new coil packs wires sparkplugs. Complete fuel system clean and replaced all fuel lines and filter including squeeze bulb. Installed brand new ECM. This all started when I had brought it in for service to install a new impeller and water pump. Any ideas here?Issue has been going on for two years now. Sometimes it works great and I can't get it to fail. I'm about to burn the boat down at this point.
Submitted: 3 months ago.
Category: Boat
Expert:  Jason replied 3 months ago.

Hello my name is ***** ***** am I speaking with?

Have you duplicated the problem and then checked for spark to see if it was in fact loosing spark, or not?

Customer: replied 3 months ago.
It has a spark. I know because I accidentally got zapped.
Expert:  Jason replied 3 months ago.

If it has spark then it has to be dropping the injector. Have you listened to it with a stethoscope to see if it stopped clicking when the problem was happening?

Customer: replied 3 months ago.
I'll try it today. I plan on taking it out again to see if I can diagnose it. While I'm there if there is a clicking then what? If no Clicking then what? I'm just trying to speed things up. Thank you.
Expert:  Jason replied 3 months ago.

Let me ask you this, how are you making the determination that the #2 cylinder is not firing. What are you doing seeing or touching to make that determination?

Customer: replied 3 months ago.
Good question. To figure out which was down I went down the line pulling the plug wires. When I pulled #1 the motor ran worse. When I pulled #2 no change. I pulled #3 and #4 and it ran worse. Then I pulled the wire harness attached to the injectors. Again, same logic here. When I pulled #2 no change in engine performance. I also had this at two Merc dealers who had this hooked up to the laptop and all it said was #2 shut down. I brought it to the god of Outboards and he replaced the thermostat and sid that the motor was never getting to optimal temp so it was shutting down a cylinder. I took it out this weekend sice that repair and the same problem exists.
Expert:  Jason replied 3 months ago.

I don't want to speculate as there could be one of a million different things going on. Get a timing light as well as a mechanics stethoscope, take the boat out, duplicate the problem. When it's running poorly, hook up the timing light to the #2 coil and see if the timing light flashes or not. If it does flash, listen to the #2 injector and see if it's clicking or not. If your not sure what it should sound like, just listen to the ones that are firing. Let me know what you find.

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