Won't start

[Miker031278]

Mercruiser i/o won't start in morning but has no issue starting in the afternoon. Anyone with any ideas. Changed all ignition parts distributor cap ignition coil ignition wiring?

[Boatapedia]

Well, here are some aspects to consider:

1) Cold Engine: In the morning, the engine is typically cold, and cold-start conditions can differ from those in the afternoon when it's warmer. Cold temperatures can affect the engine's performance.

2) Battery Voltage: Cold weather can affect battery performance. Ensure that the battery has sufficient charge and is in good condition. Cold cranking amps (CCA) are essential for starting in colder temperatures.

3) Fuel System: Cold temperatures can affect the fuel system. Ensure that the fuel lines, filters, and carburetor (if applicable) are clean and not clogged. You might consider using a fuel stabilizer during the winter months.

4) Choke or Fuel Injection: Depending on the engine type, you might have a choke (for carbureted engines) or electronic fuel injection. Ensure these components are functioning correctly. For carbureted engines, the choke may need adjustment.

5) Spark Plugs: Although you mentioned replacing ignition components, make sure the spark plugs are in good condition, properly gapped, and not fouled.

6) Starter Motor: Cold temperatures can affect the starter motor's performance. If the issue persists, consider having the starter motor checked for any potential problems.

7) Timing: Check the ignition timing to ensure it's set correctly. Timing that's too advanced or too retarded can affect starting, especially when the engine is cold.

8) Air Intake: Make sure the air intake is clear of obstructions and that the air filter is clean.

9) Compression: Low compression can make cold starts more difficult. If other factors don't resolve the issue, consider having a compression test performed to check the engine's health.

10) Professional Inspection: If you've checked all the above factors and the issue persists, it may be beneficial to have a marine mechanic or technician inspect the engine. They have the tools and expertise to diagnose and address the problem effectively.

I know your post is from a while back, but I hope this helps someone.