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  1. #1
    Chief Petty Officer
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    Default Evinrude 90 hp two stroke - fuel pump testing - how to?

    I was wondering how do I test the pressure or flow rate of my fuel pump on a 1981 Evinrude 90hp two stroke engine. I don't have any gauges or flow rate meters. The motor is hard starting some times

  2. #2
    Commander
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    Feb 2012
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    Default Re: Evinrude 90 hp two stroke - fuel pump testing - how to?

    motor starts off the priming bulb so if the bulb pumps until it becomes firm then its proberly not the pump unless its flooding with gas. the pump failing will normally show up when engine is under power. the carbs will starve for gas and the simple check is to get someone to pump the primer if the motor picks up then its proberly the pump. pressure can be tested but unless you have a base line for what its meant to read then it proberly wont help. (does your fuel bypass valve click when you press the key in?)

  3. #3
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    Default Re: Evinrude 90 hp two stroke - fuel pump testing - how to?

    Easy to test. Disable ignition so motor can't start, disconnect fuel pump outlet hose and direct the outflow to a pail. Crank motor over with starter ... you should get strong fuel pulses. Feeble pulses suggest a bad fuel pump.
    Jim

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  4. #4
    Chief Petty Officer
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    Default Re: Evinrude 90 hp two stroke - fuel pump testing - how to?

    Quote Originally Posted by wilde1j View Post
    Easy to test. Disable ignition so motor can't start, disconnect fuel pump outlet hose and direct the outflow to a pail. Crank motor over with starter ... you should get strong fuel pulses. Feeble pulses suggest a bad fuel pump.
    This basically what I always did but this is with the VRO pump not sure if anything was different. Motor starts, runs okay but sometime when its hot and sits for 20 - 30 minutes it very hard to start again. Not sure if its flooded or starving for gas or if its even gas related - almost everything else has been replaced or rebuilt

  5. #5
    Petty Officer 3rd Class
    Join Date
    Feb 2010
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    Default Re: Evinrude 90 hp two stroke - fuel pump testing - how to?

    Hi,
    I have the 50HP Johnson and i was having the same issues as you have mentioned, when started from cold it would start first crank and the same if restarted with in 5-10 mins of switching off, However if it was left to sit for anything more than about 30 mins to a few hours it would be a real pain to restart it.
    Turned out to be the mechanic who serviced it before i bought it had put the wrong plugs in it,So i swapped them out for the right ones now when i start it she fires up first crank all the time now does not matter how long it has been off for.
    So being that is a simple thing i'd check that first.
    Have a look in BRP_SparkPlugChart2007.pdf and check you have the right ones they should be Champion branded
    If they are fine then as mentioned previously take the fuel line off and run it into a bucket and check for strong pulses of fuel when cranking.
    Good luck

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