Search results

  1. C

    350 Mag MPI Horizon died at sea, cannot find the problem.

    Ran the boat for 35 miles on the ocean this Sunday, engine was reliable. Generally I clean the contacts inside the distributor 2x/season with a soft stainless wire brush in a Dremel tools. Otherwise corrosion builds up. This is an older boat where all the water drains into the bilge. I have...
  2. C

    350 Mag MPI Horizon died at sea, cannot find the problem.

    The Fuel Injector fuse was out, thanks for the professional help. I did not know there were fuses under the cover... Charging system worked excellently today. On the day the engine died, upon starting the boat the idle was too high, ~1100 rpm. I unplugged the IAC connector, engine died, but...
  3. C

    350 Mag MPI Horizon died at sea, cannot find the problem.

    Thanks, I will check those. Are they glass fuses or mini blade fuses?
  4. C

    350 Mag MPI Horizon died at sea, cannot find the problem.

    I will be back at the boat on Friday, and will check the cranking voltage. Any idea where the 12 volt injector fuse is, if it has one? Looking at my schematic, I see that the two light wires in the coil connector are parallel. Will check the voltage there as well.
  5. C

    350 Mag MPI Horizon died at sea, cannot find the problem.

    12V injector fuse, I will have to find that, did not know it existed. Swaped in a used cap and rotor, no change. For the coil, put the probes on the white and pink wires? Connector has a pink plus two light colored wires. Starting voltage was back up to 12.7 volts, I have a Blue Sea digital...
  6. C

    350 Mag MPI Horizon died at sea, cannot find the problem.

    We had been running for an hour, engine appeared to be running well. Engine just stopped. Checked for spark, nothing from the coil wire. Also battery voltage was low. Engine has 1800 hours on it, coil and both fuel pumps replaced 500 hours ago. 2006 (?) model, s#OM675521. Was towed 15 miles...
  7. C

    Recommended anti-seize when assembling drive and transom shield?

    What are recommended anti-seize compounds to use?
  8. C

    Having trouble removing SX-M gimbal bearing seal

    I have been using a slide hammer puller with both the three jaw attachment, plus the single hook/ledge style attachment. Having no success. Tried using a long, sharp screwdriver to cut into the seal, no luck. Any suggestions? When I use the puller it feels like I am hooked on a solid piece of...
  9. C

    350 Mag MPI will not run at 800 rpm.

    2006 Merc. 350 mag MPI, Horizon model. Idles great, runs fine at 1100 rpm and above, but when setting the throttle in the 700-900 range, the rpm's drop down to 625 after a few seconds. I thoroughly adjusted the control cables and control, which had no effect. Would a small vacuum leak cause...
  10. C

    Which inconel vavles for my Mercruiser Vortec heads?

    I posted a few weeks ago about probably needing valve work on my heads. I believe I was overpropped, and overheated the exhaust valves. I never did a max rpm test with the boat loaded, only with one person and in smooth water. Typically we will be out fishing in 4 foot seas with four persons...
  11. C

    Which new Vortec cyl. heads for my 350 Mag MPI motor?

    I have a 2006 350 Mag MPI Horizon engine with 1,700 hours on it. Boat is a heavy 24' SF boat. I pulled the heads at 1250 hours, did a valve job with two new exhaust valves. Also changed the timing chain at that time. My boat is only used in salt water. Engine has no blowby, but has become very...
  12. C

    Portable oscilloscope?

    I would like to measure the coil output on my Merc. 350 MAG MPI engine. A portable oscilloscope would probably be best. Any recommendation on buying one? I notice that there are some portable gap jump test tools for very low cost. They might work satisfactorily.
  13. C

    Need internal voltage regulator for Mercruiser alternator.

    The alternator in my 350 Mag MPI Mercruiser is overcharging, so I assume I need a voltage regulator. Mercruiser does not sell the regulator separately. I notice there are some on Amazon, but I am wary about another Chinese or other cheap part. Any recommendations on where to buy a regulator?
  14. C

    350 MAG MPI sterndrive, low raw water pressure, does it need an extra through hull?

    I installed a moderately used 350 MAG MPI Horizon in my sterndrive boat. The Guardian system is triggered due to low water pressure, and I verified this with a manual pressure gauge. I am only getting 3 psi at all speeds, despite a new impeller. The prior owner of the engine had a...
  15. C

    Trying to bypass Trim Limit Switch on 2006 MCM 350 Mag MPI, with Volvo SX outdrive.

    I have installed a Mercruiser 350 Mag MPI engine in my boat that has a Volvo SX outdrive. Everything is working correctly, except that the engine is in Guardian Mode and is limited to 2,800 RPM. Apparently I have to install or mimic the Trim Limit Switch so that the computer will not put the...
View older results
Top