Recent content by isaacs

  1. isaacs

    Antifreeze Question

    My boat runs flawlessly and has never had any rust coming out of the manifolds or engine block when I drain it. So why am I complaining? The price of pure propylene glycol antifreeze, which I have always used, is up to $8/gallon at Home Depot. I'm tempted to either use the cheap stuff (half...
  2. isaacs

    Ignition sensor help

    I would use nothing that is not Mercruiser or Quicksilver. People on this forum have had trouble with the aftermarket stuff. Sierra is tempting, but I wouldn't use it. Just a tip: Mine had a nut with a little ground wire on the bottom of one of the mounting screws that had to be loosened...
  3. isaacs

    Fogging oil won't kill engine

    If you stay away from ethanol contaminated fuel you shouldn't need any additives or fogging for a simple winter layup. Just shut it off and have a beer!
  4. isaacs

    Thunderbolt 5.0 keeps dying

    Have you ever replaced the ignition pick-up in the distributor? If you still have the old two wire "open" style (you can see the little circuit board) replace it. You may still be getting a weak undependable spark which is just enough to trigger your timing light but not enough to ignite your...
  5. isaacs

    Runs great on muffs but not in lake

    Could there be water in the bottom of your fuel tank that's making it's way to the fuel pickup when the boat sits at a different angle in the lake?
  6. isaacs

    Troubleshooting a leak

    Can you get someone into the water and have them wiggle the shift bellows around while you observe from the inside? If the drip rate changes, you've found your problem.
  7. isaacs

    No start situation

    Make sure you have 12 volts while you're cranking, not just with the ignition switch "on".
  8. isaacs

    No start situation

    Try putting a jumper wire directly from your battery plus to your coil plus. This will bypass a lot of wiring and switches.
  9. isaacs

    04 Mercruiser 5.0 bogging down @2500rm

    My money is on your ignition sensor in the distributor. It's the little thingy at the bottom that the rotor fins pass through. When they start to go bad you get a weak spark which, in my case, seemed to get worse as the day progressed. Check to see of you have the old "open" type--you'll be...
  10. isaacs

    Sticky Throttle cable? Shift Cable? Help!

    So if it can be easily shifted into neutral with the engine off that kind of means there is nothing wrong with the shift cable; it must be the switch or a poorly adjusted throttle cable.
  11. isaacs

    Sticky Throttle cable? Shift Cable? Help!

    If you try shutting the ignition key off when you try to pull the shifter out of gear what happens?
  12. isaacs

    5.7L 1984, Rough idle at start up, then ok after a minute or so

    I got mine a couple of years ago at a local marina. It was either Mercruiser or Quicksilver (same thing). Here's Amazon: https://www.amazon.com/Quicksilver-Distributor-Sensor-892150Q02-Thunderbolt/dp/B001HBN0YY/ref=sr_1_3?keywords=mercruiser+ignition+sensor&qid=1653312049&sr=8-3 This looks...
  13. isaacs

    5.7L 1984, Rough idle at start up, then ok after a minute or so

    My old style ignition sensor was intermittent when it bit the dust--tortured me for an entire summer 'till I tracked it down. The engine would cut out, mostly when I was on plane. It was as if someone was briefly switching the ignition switch off and back on again--all my gauges flipped to...
  14. isaacs

    5.7L 1984, Rough idle at start up, then ok after a minute or so

    Try a jumper from the battery + to the coil +.
  15. isaacs

    Why is my carb oxidizing????

    You have rust and corrosion on every unpainted surface in that engine compartment, not just the carburetor,. What does the rest of the boat look like? Like under the dash--rusty bolts or funky looking electrical connections? It could be a clue if everything inside the boat is rusting. Any...
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