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Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3937
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
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2007 Mercury 25 HP 4 Stroke. Starts and runs great! Shut off

Customer Question

2007 Mercury 25 HP 4 Stroke. Starts and runs great! Shut off to fish for 1 hour or so and it won't start. Turns over fine but won't fire. Let it sit longer, troll for 30 mins to 1 hour and it starts up perfect. Twice this has happened. Fuel in bulb and filter. Try starting in between several times but nothing. Then perfect.
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Is there anything else important you think the Marine Mechanic should know?
Customer: Always starts first time when put in water. Or at house with cups. Just won't after running and sitting. Serial number OR165543
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Marine Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you.

When was the last time that the engine functioned correctly?

When was the last time that the cooling system was serviced?

Customer: replied 1 year ago.
last year prior to having it winterized.
A couple years ago.
Customer: replied 1 year ago.
If I shut it off from trolling to realign a fish it starts up again. Only won't after sitting for a while. Maybe 30 mins.
Expert:  Charles replied 1 year ago.

Does the primer bulb ever go soft or collapse?

Customer: replied 1 year ago.
No, not soft. Just normal. Had thought vapor lock. I've squeezed it to check when trying to start.
Expert:  Charles replied 1 year ago.

Could you move any fuel with it when this happens?

Customer: replied 1 year ago.
I unplugged the fuel line, checked for flow. Squeezed bulb and depressed the connection pin. Fuel came out. Also during disconnecting the line it would squirt a bit from pressure. I unscrewed the fuel filter and it looked clean filled up fine.
Expert:  Charles replied 1 year ago.

Ok. The water pump for your engine is recommended to be replaced every 2 years. you could just have a lack of cooling water to the engine and it is getting too warm inside the cover when it is in its heat soak period.

Customer: replied 1 year ago.
I'll take a look but it seems to flow very well the water never feels warm coming out. The impeller was replace about 3 years ago.
Customer: replied 1 year ago.
What about the coil packs or injectors. Anything I can check for these?
Expert:  Charles replied 1 year ago.

Injectors would sound an alarm. the coils, either work or dont. this engine will even run on one cylinder.

The water flow on this engine will not get hot at the tale-tell. It splits at the bottom of the exhaust plate, goes through the fuel cooler, then the pulse pump, and out of the engine. Even if you have good flow there. The engine may be just getting enough to not throw the overheat code.

Customer: replied 1 year ago.
Is there a way to test for this? Or trouble shoot?
Expert:  Charles replied 1 year ago.

For water flow or the injectors and coils?