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  1. #1

    Question 07 EFI 90HP Strange Fuel Issue

    I have a 2007 EFI 90HP four stroke that has a peculiar problem.

    This engine was sitting for some time but ran sporadically. I've dumped the fuel, changed the tank to engine fuel line, replaced fuel filters with OEM filters, changed the spark plugs, replaced engine oil, and gear oil.

    The engine fires right up, idles great, and runs wide open for as long as I want, I'll get it going 40 mph going upstream in the lower Missouri without a problem. I can back and forth the throttle and even abruptly drop it to idle without issue, the engine will seemingly run the engine like this until I run out of gas.

    The issue comes when I decide to turn the engine off. Last week I drove the motor for about 20minutes without any alarms or problems, turned the motor off, let it sit for about 5 minutes and started it up.

    After turning off the engine it appears to be fuel starved (sputtering, shaking, loss of power and eventual shutdown). This problem is fixed if I continually pump the bulb. I'll take the boat out of the water and let it sit for a day and this same process can be repeated. Do I have an engine that just needs to stay on?

    I've taken off the FSM and inspected the gaskets at the fuel pumps, they could probably be replaced. I've also inspected the screens on the pumps and see no debris.

    My initial thought is that I have a faulty float sensor. It appears that once I shut the engine off my lift pump is not being told to run and thus starving my high pressure pump, I believe this to be true given that the problem can be alleviated by using the bulb on my fuel line. Thoughts?

    What is confusing is that I am able to run perfect for what as long as I want, but once the engine is shut off the problem occurs. Again, no beeps were heard while running full out.

    Thank you for your assistance.

  2. #2

    Default Re: 07 EFI 90HP Strange Fuel Issue

    We have an identical issue with a 2006 100hp efi
    Engine was idle for a while also.
    We have replaced filters, fuel lines, etc
    Starts cold every time, runs great. Issues start if it is turned off when hot it acts as if it is fuel starved.
    Once cold, starts perfectly again.
    Allso Interested in any advice on steps to diagnose this issue.

    Thx in advance for any help and/or guidance



    Quote Originally Posted by MOutdoors View Post
    I have a 2007 EFI 90HP four stroke that has a peculiar problem.

    This engine was sitting for some time but ran sporadically. I've dumped the fuel, changed the tank to engine fuel line, replaced fuel filters with OEM filters, changed the spark plugs, replaced engine oil, and gear oil.

    The engine fires right up, idles great, and runs wide open for as long as I want, I'll get it going 40 mph going upstream in the lower Missouri without a problem. I can back and forth the throttle and even abruptly drop it to idle without issue, the engine will seemingly run the engine like this until I run out of gas.

    The issue comes when I decide to turn the engine off. Last week I drove the motor for about 20minutes without any alarms or problems, turned the motor off, let it sit for about 5 minutes and started it up.

    After turning off the engine it appears to be fuel starved (sputtering, shaking, loss of power and eventual shutdown). This problem is fixed if I continually pump the bulb. I'll take the boat out of the water and let it sit for a day and this same process can be repeated. Do I have an engine that just needs to stay on?

    I've taken off the FSM and inspected the gaskets at the fuel pumps, they could probably be replaced. I've also inspected the screens on the pumps and see no debris.

    My initial thought is that I have a faulty float sensor. It appears that once I shut the engine off my lift pump is not being told to run and thus starving my high pressure pump, I believe this to be true given that the problem can be alleviated by using the bulb on my fuel line. Thoughts?

    What is confusing is that I am able to run perfect for what as long as I want, but once the engine is shut off the problem occurs. Again, no beeps were heard while running full out.

    Thank you for your assistance.

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