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    mercruiser 5.0 mpi slowly overheating

    Got my boat out for a test run today and it runs great except that after about 30 minutes of running about 75% throttle it overheated. Shut it off for 3 minutes and restart. immediately cooled down. Ran a bit longer and the temp was slowly climbing again and I stopped but didnt shut it down...
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    Octane recommendation in 5.0 mph mercruiser

    I have been running 89 from the pump with ethanol bc I can find gas without it. I use Star tron additive to help with this. Is there any reason I couldn’t run 87 and get a little more? What’s everyone’s opinion on this?
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    Alpha one gen 2 bumped out of gear but stuck in gear?

    So i was cruising across the lake today at high speed and my drive sounded and felt like it shifted out of gear and back into gear suddenly while cruising. I immediately put it in neutral but the engine stalled. Cant turn like the drive is stuck in gear. I noticed recently that the drive...
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    98 Trophy 2352 top speed and fuel economy.

    So I finally got my motor back together and tested out several times on my local lake and I don’t think I could ask for more. It’s got the 5.0 mpi mercruiser with an alpha one drive running a 17 pitch revolution 4 prop and on the lake it’s topped out at 41 mph at 4700 rpm. At this speed I was...
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    5.0 mpi overheat at higher rpm.

    Finally got the heads back and on the boat. Runs great but at higher rpm it will overheat and wont cool off unless I shut the motor off for about 2 minutes and restart. Then the temp drops rapidly. Ive noticed if you are looking at the motor the left riser on the exhaust gets pretty warm...
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    Few questions about engine condition and parts differences. 5.0 mpi

    Ok so I left off with finding my heads were completely wasted. Deformed and Leaking intake valves and both heads cracked. After looking things over I found the water passages on the bottom or outer part of the cylinders as well as the heads were plugged solid with metal debris. I had to clear...
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    5.0 mpi losing power after warm up

    I figured i should just start over since im down to one problem and noticed more of whats happening with my motor. As stated in my previous post Ive completely removed and cleaned out the fuel tank, changed the cap, rotor, plugs , wires, fuel filter, all injectors, and oil change with...
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    Engine wont start in the water. Then loses power at full throttle.

    Hopefully someone can point me in a direction here. Ive done searches here and on several other sites but cant find a solution to my problems. First with the details. Ive got a 2003 mercruiser 5.0 Mpi with an alpha one gen2 outdrive. First problem. The engine starts no problem on land but...
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