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Recent content by makomark

  1. makomark

    1971 Mercruiser 140 Ignition Issues

    When you checked voltage at the + post on the coil was the engine running or not? The norm is about 3 vdc less with the engine running... Finally, have you checked the point since the last use, to see if they have degrade? You may as long want to check the condition of the key switch if it's...
  2. makomark

    4.3 Mercruiser Vortex

    I'd check the engine side of the ground cable...
  3. makomark

    5.7l Black Scorpion intermittent starting

    If there's 12VDC at the slave solenoid when the key is OFF, I'd be worried about damage to the wiring harness - could be either the engine harnesss or the instrument harness...separating them and rechecking will yield insights...
  4. makomark

    5.7l Black Scorpion intermittent starting

    post #8 has a different wiring diagram than shown in post #6... either way, with the key = START, if there is no voltage drop across the slave solenoid's coil, then the ground connection is at fault - whether its a wire or a bad connection...
  5. makomark

    5.7l Black Scorpion intermittent starting

    with the key=START and the Neutral safety switch=OPEN, seeing +12VDC on both small posts is 'normal'. Pretty sure +12VDC comes from the key switch, in START, via the RED/YEL wire, and GROUND is provided, thru the YEL/BLK wire, when the Neutral safety switch is closed (in Neutral).
  6. makomark

    Gen IV crank mounted pump conversion questions.

    Usually better to start your own thread vs piggybacking on one thats over seven years old... There should be three thru bolts on the flange of the pump, that go thru the v-belt pulley and bolt to the balancer....
  7. makomark

    Looking to source a fuel pump for my 1985 Crusader 454 I believe they're called Mark 4. Engine serial number is 55512

    tnx
  8. makomark

    Engine not shutting off with key

    has there been any maintenance actions before the engine doesn't shut off issue started? if there's no +12VDC on the terminal of the igntion switch (with the key OFF) then something appears to be wrong in the wiring. Can you verify +12VDC at the ignition coil with the key ON, then start the...
  9. makomark

    Looking to source a fuel pump for my 1985 Crusader 454 I believe they're called Mark 4. Engine serial number is 55512

    so who offered the 'not-so-good' part? MFG #?
  10. makomark

    Engine not shutting off with key

    Pretty sure that vintage uses the MSTS ECU system....mostly to control the ignition timing. On those, the ignition coil is fed power from the system relay...and that should be controlled by the ignition switch. I'd start with that (relay with contacts stuck together)....as far as turning the...
  11. makomark

    Overheating issues

    Are you loosing coolant?
  12. makomark

    Exhaust Extension Riser For Alpha One Gen II

    maybe the BARR riser, MC-20-61851A3 will work for you...buts it is only 3". Barr also had a MC-20-61851A2 kit that had a 'pair' of risers...if you want 6", that may be cheaper in the long run...but you'll like have to find alternative fasteners.... FWIW, I doubt the 3.0l will be happy pushing...
  13. makomark

    Overheating issues

    I've seen a few cooling issues where the pump was "rebuilt" and the reality was the impeller and gasket were changed...the wear parts were overdue ...and we know how that works. What's unique is that the system appears to cool up to the 2200+/- RPM point and then goes hot...that suggests...
  14. makomark

    Overheating issues

    The clear hose in the product side of the raw water pump isn't the same as the strainer...the "headspace" won't last long...but thats his choice..
  15. makomark

    Overheating issues

    i believe you...just trying to understand what was done vs what wasn't done...tnx!
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