Mercury black max 150

Discussion in 'Bubba's Outboards' started by psychomekanik, Jul 12, 2008.

  1. psychomekanik

    psychomekanik New Member

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    2,534
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    Illinois
    My friends dad just bought a boat and is having problems with it already. He's a good ol' boy and I'd love to help him out. but I'm stuck. His engine is an 86 mercury black max v-150 ser.# oa960302 the problem is his alarm keeps going off in short beeps. I'm assuming a solid tone is an overheat and the broken tone is an oil alarm, Correct? so here's what i found. It has an oil resivior in the back of the boat and a small one on the engine. the one on the engine has a float that looks like it would trigger the alarm when it gets down to just above a half of a tank of oil. the engine uses crankcase pressure to "push" the oil out of the main resivoir to the one on the engine. the resivoir on the engine was'nt completely full. I suspected an air leak at the main tank causing poor flow to the secondary resivoir. it has good pressure at the air line on the primary tank and it seemed to have good oil flow from the primary to the secondary at the fitting on top of the secondary. I checked it out and everything seemed to work fine. but the secondary was a little low. I checked float operation with an ohm meter, it works fine. I put it all back together and ran it with the secondary cap off to make sure it vents and fills properly and it works fine. so, I suggested that he HAD an air leak at the primary tank cap and to check the airlines with soapy water. we filled up the tank and ran it again and as soon as we turned on the key the alarm went off for a few seconds again. so i looked at it again thinking maybe we had the float hung up or something. this time I tried to force the alarm to go off by manually lowering the float. we can't even get the alarm to go off manually. I would think as soon as that float bottoms out the alarm is going to go off. the system has a sensor in the oil pump, a float in the secondary resivoir and the injection moniter. all connections are clean and good. I'm not so worried about an intermittent alarm as much as i am about the alarm not going off when triggered. can someone shed some light on the situation for me. possibly give me a rundown on how the system works. How does the 3 wire sensor in the oil pump work, and how to test it, why does the alarm not go off with a low float setting, and any common problems ?? Thanks in advance to anyone that can help me...
     
  2. Bobpaul

    Bobpaul New Member

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  3. psychomekanik

    psychomekanik New Member

    Messages:
    2,534
    State:
    Illinois
    Thanks Bob, I think I'll have him buy a service manual and check it out thoroughly. and possibly get rid of the oil injection pump, and just premix. I think the module itself is bad. but for what it costs to replace. it's just not worth it if he might end up shearing a plastic gear and frag the motor after all that.
     
  4. Bobpaul

    Bobpaul New Member

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    3,039
    State:
    Supply NC
    They also had a problem with their lower units being too weak. They'd send gears out the side of them.

    DH has one of them that was rebuilt, with the standard lower unit. I've replaced them before, and the upgraded lower unit is much bigger. The prop from the standard lower unit, won't fit the upgrade prop shaft.