Can I do away with fuel solenoid?

Discussion in 'Mechanic and Repair' started by emtigene, Jun 19, 2013.

  1. emtigene

    emtigene LawnSite Member
    Posts: 3

    I have a Kawasaki FX730V, 26 HP, only 62 hours. Engine will not run, installed new plugs and new fuel pump. With talking to mechanic and online research I am thinking the solenoid is not working. With a price tag of around 130.00 I am wondering if I can do away with it and if so how to go about it. I would greatly appreciate any help you could give me.
     
  2. BleedingGreen

    BleedingGreen LawnSite Member
    from SE MI
    Posts: 165

    You should hear a click when you turn the key to the run position (don't crank just run position) from the fuel solenoid. This click is the fuel solenoid opening. You can also bench test this with 12 volts. I've even used a 9 volt battery. When the fuel solenoid sees power the plunger retracts allowing the fuel to flow. It might not be a bad idea to take it out anyway to see if there is debris blocking it too.
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  3. BleedingGreen

    BleedingGreen LawnSite Member
    from SE MI
    Posts: 165

    Oh and to answer your question, in theory yes you could bypass the fuel solenoid. Either remove the plunger from the fuel solenoid or if you had a safe way to block the opening where the fuel solenoid would be if you removed it (not recommended) . All the fuel solenoid does is prevent fuel from flowing while shutting the engine down to prevent backfiring while the engine is still turning but the ignition is off since the created vacuum is pulling fuel.
     
    Last edited: Jun 19, 2013
  4. dboyd351

    dboyd351 LawnSite Bronze Member
    Posts: 1,099

    BleedingGreen - sort of a question/comment - I was wondering if the solenoid would also keep all the fuel from draining into the crankcase if the needle seat failed in a float bowl carb? I recently had all the fuel drain from the gas tank into the crankcase on a motorcycle because the needle valve controlling flow into the float bowl got stuck open. Seems like the solenoid would have prevented this - No?
    Either way, it isn't something you need unless you have a float bowl carb and your needle valve fails.
     
  5. taxidermist

    taxidermist LawnSite Member
    Posts: 49

    Take it apart and clean /lube it. I dont see many go bad but I do find a lot of them stuck.


    Rob
     
  6. BleedingGreen

    BleedingGreen LawnSite Member
    from SE MI
    Posts: 165

    Dboyd351- typically no. The fuel solenoid does not create a 100% seal. You would think it does due to it's name and purpose but typically the main jet also has other ways(slots, holes, etc.) of allowing fuel to continue to flow, usually beacause of gravity I.e. fuel tanks, lines, etc. that are higher than the carb. Even faulty fuel shutoffs. So if you have a needle and/or seat problem, while slow will still allow your condition to occur.
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    Last edited: Jun 19, 2013
  7. BigFish

    BigFish LawnSite Silver Member
    Posts: 2,915

    The "fuel solenoid " as it is used on most all small engines, only controls/stops the gas from entering the main jet/nozzle. It usually is called an "anti- afterfire" solenoid in most IPLs.
    It has nothing to do with fuel flowing thru the inlet needle and seat. In most cases, if the float/needle gets stuck in the open position the carb will still overflow and fill the crankcase with gas!

    And yes, all ya gotta do is snip the end/tip off the solenoid.
    It helps to stop the backfire if you let the motor idle down a bit to cool off before shutting off.
     
  8. emtigene

    emtigene LawnSite Member
    Posts: 3

    Thanks guys. It will be this evening before I can try that. It makes sense that a small amount of fuel is still getting thru when setting as after it sets awhile it will start and run for about 2-3 seconds. I will let ya'll know if that is what the problem is.
     
  9. emtigene

    emtigene LawnSite Member
    Posts: 3

    So I took off the solenoid and held my finger over the hole while my son started the engine (not recommended). It fired up immediately and run fine. We cut the plunger off and reinstalled solenoid, mower is running like new. Thanks again for the replies to my questions.
     
  10. BleedingGreen

    BleedingGreen LawnSite Member
    from SE MI
    Posts: 165

    Good glad to hear it. Curious to know if it actually failed, debris, electrical problem, etc though. Glad it's running again!
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