Fuel Pump Problems?

Discussion in 'Bubba's Outboards' started by catfishcentral, Jun 8, 2006.

  1. catfishcentral

    catfishcentral New Member

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    I have a 1995 Yamaha 75 hp and as far as I know the fuel pump as never been replaced. The other weekend it died on me twice and sure sounded like it wasn't getting fuel to the carbs. I ended up having to pump the ball to get fuel going into the carbs and it ran fine after both times. I got home and check the fuel filter for any clogs or debris and fuel lines for any leaks. Everything looks good and I suspect that maybe it's just time to replace the fuel pump. Tonight I went out again and after two hours on the boat I began to have problems again. I was running pretty close to full throttle and it sounded like it was running out of gas. The motor never died but came close and then would run fine for awhile. The carbs are not a problem with this motor and the fuel line and filter seem to be in good working order. Would I be safe to assume the fuel pump is the culprit or is there anything else that could cause a problem. Also I believe someone told me that a rebuild kit mainly consisting of a new diaphragm I believe would usually solve the problem and be more cost effective. Would I be better off rebuilding the pump or just buying a new one. I have no idea how much one is new but I bet I can't get out of the store for probably less that 150.00 bucks.

    Thanks
     
  2. Bobpaul

    Bobpaul New Member

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    Is there an built in fuel tank or a remote tank?
     

  3. catfishcentral

    catfishcentral New Member

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    This boat has a 12 gal portable tank.
     
  4. Bobpaul

    Bobpaul New Member

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    Yamaha fuel pumps are very reliable, but things can happen.

    You can take off your fuel pump and clamp it together like it would be as if mounted on the engine. Pressurize the system by pumping the fuel line bulb and see if gas leaks out the pulse hole in the back of the pump.

    If it leaks, rebuild it, if not, look else where. Fuel tank pick up, primer bulb valves sticking, even carb needle valves sticking closed.
     
  5. catfishcentral

    catfishcentral New Member

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    Thanks Bob!! I'll check everything else out before taking the fuel pump off and testing it.
     
  6. Bobpaul

    Bobpaul New Member

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    I mentioned the fuel pump check out first because if it's leaking into the pulse hole, it's leaking raw gas if you've got oil injection.

    That gas will wash your bearings of oil and there goes the rod in the cylinder that supplies the pulse to the pump.

    The tank can be checked without running and the bulb is an easy replacement.

    I've run into your problem before with a new 12 gallon tank. The pick up tube would suck itself to the bottom at high speed and collapse the bulb from vacume.

    I asked about onboard tanks because it's required to install anti-siphon valves in them that can also cause your problem.
     
  7. catfishcentral

    catfishcentral New Member

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    Thanks for the extra info there Bobpaul. My Yamaha is not oil injected still have to mix it myself...so no problem with raw gas causing any damage. I had also talked to my local Yamaha dealership this morning and they said they really never had any problems with fuel pumps on the smaller mid range engines only on the larger V4 and V6 outboards. Makes me feel kind of better hearing from you and others that the fuel pumps are a rare problem and it's probablly something simple with the tank and hose. I will though check out the pump first to see it that's the problem as so to elimate that possibility.

    Thanks again.
     
  8. fishnfool68

    fishnfool68 New Member

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    Near Tulsa Oklahoma
    My first boat and I know very little to nothing about outboards-for starters.I fixed-up a ol'vbottom that sat in a field for years and paired it with a '57 12hp,SeaKingthat sat for at least 12yrs.My dad(knows just a little bit more than I)replaced the water pump and fuel lines.I sprayed out the carb but didn't rebuild.Ran great first 2/3 times out them started same problems as Chris's motor.I would like to know what I should do before putting this motor to use.I can't afford a new one and don't want to ruin the motor.If I have to take it to a shop what would be a reasonable price to spend to have it fixed?I work on all my cars myself and ran a auto service dept.I have seen the damage do-it-yourselfers can do,when in over thier heads.I would appreciate any advice you guys can give.Thank you in advance.
     
  9. Bobpaul

    Bobpaul New Member

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    First thing to do is please start a new thread for your problem so It can be viewed without mixing up answers. It cuts down on confusing Bubba. He's getting on in yrs and needs all the help we can give him.
     
  10. Bubbakat

    Bubbakat New Member

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    Ain't that the truth.:confident: