Search results

  1. C

    Size of outboard

    A light 16' footer with a 40HP big twin was pretty standard in the 60s. 25MPH was the max cruise.
  2. C

    1985 75 hp mercury kill wire.

    The black/yellow wire is the ign killer. Mercs used to have a mercury switch (small m) which killed the ign if the motor kicked up. They may still have had one in your year. A generic wiring diagram shows the third terminal from the bottom on the left is the killer wire terminal. It should...
  3. C

    150 Johnson will not idle

    OK, I did not know that the motor would immediately restart, and run with advanced throttle. Those motors are prone to idle lousy after restart, and even stall at idle. Some call this heat soak. Your issue seems to be more acute than usual. The work around is to let 'em idle at 1200RPM for a...
  4. C

    New control box

    You can add a separate trim button, however, it will likely need to be mounted on the dashboard. It is inconvenient, as you need three hands: one to steer, one to control speed and one to trim, while accelerating. I would expect you could get a new control with built in trim button relatively...
  5. C

    Overheating issue.

    Gee, Have you established that the manifolds are not clogged? Exactly how did you do that? You can pull the hoses off the manifolds and risers and see the water flow, when motor is on flusher. What you cannot see is if water flows thru them. Exhaust Flappers will not fix your issue.
  6. C

    very cool carb and intake manifold causing moisture

    Racer, I have never see white sludge in the intake manifold of any motor. Under your statement that would be common. I presume the white sludge is fuel mixed with water. Water can and does get into the crankcase from leaks or cracks.
  7. C

    150 Johnson will not idle

    Check for spark, when it stalls. A lot of those motors use +12VDC to the powerpack, when engine is cranking. You may therefor see spark when cranking, and not when you release the starter.
  8. C

    What goes here

    Looks like something went there. Look behind the dash and see if it has wires or a rubber tube. A tube would indicate a water pressure gauge. Wires...who knows.
  9. C

    Concerned about Hull Config / Cramped Engine Bay

    IMO, 21 foot is a bit small for an I/O for precisely the worry you have. An OB is a better way to go on a boat that size. You also get a lot more cockpit room. You do have to give up 1/2 the swim platform, however.
  10. C

    very cool carb and intake manifold causing moisture

    If you are running E15, I doubt alcohol cooling is your issue. I am not familiar with your motor, but I would be looking for water leaks into the crankcase. The likely culprits are head gasket, or cracks in the water jacket.
  11. C

    Engine running 🔥

    As Bondo said, a lot of those V8 MerCruisers had raw water pumps, with thru hull pickups, to cool the engine itself. They therefore did not rely on the OD pump to do that.
  12. C

    Overheating issue.

    Your motor should have water hoses to each manifold and each riser. There is a ball and spring device under some of the hoses that helps direct water flow to risers(if I remember correctly). The gaskets were chosen to assist this circulation system. Use the gaskets recommended for your...
  13. C

    1982 ADI Mercury 115 6 Cylinder pesky miss

    Compare your spark plugs with each other. All should be brown or black. Any that are clean, like new can indicate water infiltration into that cylinder. Your main jets in the carbs are installed and correct for the motor? It should not studder at 3000+ RPM. If so, make sure the high and low...
  14. C

    93 Johson 150hp fuel issue

    The kits are avail aftermarket. Likely Sierra and GLM make them. Make sure they cross exactly with the OEMs, by checking several sites. I had trouble with the kits on a similar motor. The spaghetti seals were real close, but not exact. The main jet is in the carb bowl. The idle jets are...
  15. C

    Overheating issue.

    Flappers are not really important. They will stop water from backing up into the manifolds, if and only if you make a quick change from high speed to no speed. That maneuver is not one you should make for a variety of reasons. Fix the manifolds/risers first.
  16. C

    Overheating issue.

    There should not be any water in the exhaust passage of the manifold. It should stay in the outer water jacket (hence the name). The trailing ends of the risers rust away first. This can let water dribble into the manifolds, thru holes or voids. Water in manifolds can easy get into engine...
  17. C

    2 Strk Carb 1990 Merc 175 - not starting when hot - warm - 30 min wait starts fine

    When you have the no start condition, check for spark.
  18. C

    johnson 150 Low Rpm

    Gee, the main jets are real easy to clean. Why not start there. If they are clogged, imagine how clogged the much smaller idle passages are. Idle passages are located in the throttle bodies, BTW.
  19. C

    Water in oil

    Post this in MerCruiser forum. Those guys are experts
  20. C

    New fuel lines on inboard tank cannot prime!

    That can work, but the empty water separator is a real issue.
Top