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    Which spark wire set for Chevy 5.7, with 90 deg. boots each end?

    Trying to find a wire set to fit my 350 Mag MPI Horizon. However I just replaced the distributor so now have a female socket type of cap. My usual marine supplier could not help me. I have been on Summit Racing, they have sets that could work, but are all made by Sierra. Now that Sierra...
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    What Chevy engine is my 2006 350 MAG MPI Horizon?

    I suspect it might be an LT1, however for many parts I believe it is compatible with engines used in 2001 C/K 2500 trucks. If so, it would not be the LT1. It is a 5.7 with a roller cam. Serial number s#OM675521.
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    Looking for a different distributor than my crab cat dist.

    Any recommendations? I have a stripped screw holding the rotor in place, so this would be a good time to swap in a different distributor than my crab cap one. Engine is the Merc. 350 Mag MPI Horizon, 2006. The ignition system is 100% electronic, computer controlled. I have lots of vertical...
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    5.7 Vortec dist, trying to seal the cap/rotor due to constant corrosion. Merc 350 Mag MPI Horizon.

    I have an older boat where the deck water drains into the bilge. Due to the high moisture in the engine area, and that it is in saltwater for months at a time, the distributor contacts corrode quickly. My current method to keep the engine running smoothly is to clean the contacts with a soft...
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    350 Mag MPI intermittent rough running.

    This engine is FWC, has 1900 hours, but I have rebuilt the heads and replaced the timing chain set. Recently it will often start out running rough, and the idle will shoot up to 1,300 rpm. If I shut the engine down and re-start, often the engine will run correctly again. However the problem...
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    350 Mag MPI question on 555 relay fuse blowing.

    A year ago I pulled the IAC cable off while the engine was idling. An hour later a 20 amp fuse blew. This fuse powers the fuel injectors and coil. Twice since then the same fuse blew, and today it blew twice more while out in the ocean. It tends to blow just after increasing RPMs to cruise...
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    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...
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    Recommended anti-seize when assembling drive and transom shield?

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