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  1. #1

    2001 225hp Optimax Cranks but Won't Start after Sitting During Winter

    I installed a 2001 225 HP optimax last year in late August myself. Everything worked fine last year and it was only used for about 2 weeks since the weather changed and couldn't find time to get it back in the water so I put it up for the winter. When I installed it I replaced in all the necessary maintenance parts like spark plugs, fuel filters, etc.

    Last week I went to start it and it cranks great but won't fire. There is a short beep, I hear the fuel pump wind, both of which are normal, and then it just cranks with no attempt to fire. Its like a safety switch is faulty. I checked the remote safety neutral switch and it depresses correctly when in neutral. I bought a new battery (800 CCA, 1000 MCA) even though the one from last year was new and the same thing happens. On the mercury multi function gauge the voltage decreases to about 9.2 - 9.1V while cranking. According to the manual this should be OK since in the trouble shooting section it states "Weak battery or bad starter motor, battery voltage drops below 8 volts while cranking (ECM cuts out below 8 volts) (Fuel pump requires 9 Volts)."

    So I think there is a kill switch problem but I am not sure if there is one on the engine side.

    Another thing of note is this rigging didn't include a Lanyard stop switch. Wasn't an issue last year since the wires at the switch are not connected to anything, same as last year and it ran fine.

    Any advice on how to proceed from here would be a great help.

  2. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #2
    If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

    Check the basics: Compression, Spark and Fuel Quality/Delivery/Air-Fuel Pressures.

    That battery may not be sufficient, since it is the absolute bare-minimum requirement for the engine ALONE (with no boat or accessories in the boat).

    Note sure where you read the voltage numbers, but it takes 9.5V minimum (while cranking) to hold the MPR (Main Power Relay) contacts closed. If those contacts don't remain closed, you have no spark and no fuel (even if the starter is spinning).

    Make sure it's not just insufficient battery: And make sure the cable connections are CLEAN, engine cables installed FIRST, remaining lugs Largest to Smallest, and finish off the connections with a Stainless LOCKNUT (do not use wing-nuts).


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  3. #3
    The serial number is OT343633. I will check the Compression, Spark and Fuel Quality/Delivery/Air-Fuel Pressures next. I wanted to make sure I am not missing some kill switch somewhere since everything cranks normally and sounds fine, but it won't fire.



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