Mariner Magnum 150hp EFI problem

[LuistLTZ]

Hey guys! I have a 1996 Mariner Magnum 150 EFI serial # 0G337303 that I'm having a problem with. Lately it's been happening more often too. It will sometimes not want to plane. I will trim it down and get on the throttle and it will rev but sounds kinda "stuck". If I turn it off then turn it back on it will work like normal again. It has a hot foot by the way. Any ideas what I'm dealing with here?

[JOE54]

disconnect idle stabilizer , mounted on stb side of block will have connections at switch boxes, red with white strp and white with black strp disconnect it and go run it / they hang up timming

[LuistLTZ]

disconnect idle stabilizer , mounted on stb side of block will have connections at switch boxes, red with white strp and white with black strp disconnect it and go run it / they hang up timming

So run it with the stabilizer disconnected? Do I leave it permanently disconnected or put it back after running it? Thanks

[Sunny Jim]

I had a mystery problem with a '98 Mariner 200 HP. Finally took it to a local mechanic. He had it for a few weeks working on it when he had time. Finally found that the fuel pressure regulator on top of the VST had some crap piled up in it. Cleaned it out and it ran fine.

[LuistLTZ]

Since mine stops doing it when I turn the motor on and off it makes be think it's an electrical issue. But there's no telling with an outboard.

[LuistLTZ]

Would this be it? It's on the port side not starboard though.

[JOE54]

yep that's it leave it unhooked run it, if prob stops you can discard it

[LuistLTZ]

Gotcha! No issues with timing after unhooking it? I've read it can throw it off or something.

[JOE54]

that module is for idle timming not max advance

[LuistLTZ]

Ok, thank you again. I will try it this weekend.

[EuropeanAM]

If you're removing the module, I would strongly recommend verifying the timing (complete Sync-n-Link Procedure would be prudent).

[LuistLTZ]

If you're removing the module, I would strongly recommend verifying the timing (complete Sync-n-Link Procedure would be prudent).

This is exactly what I had read about. I have no idea how to do that. Would it be better to just replace the module?

[EuropeanAM]

If it were me, I would NOT replace the module. Common problem point and the engine will perform fine without it, IF properly setup/synched.

[LuistLTZ]

If it were me, I would NOT replace the module. Common problem point and the engine will perform fine without it, IF properly setup/synched.

I don't trust my local Marine shop enough to work on this issue and don't know how to do it myself. Not even sure that the module is the issue yet either. While running it today (module still connected) it shut off at wide open throttle. It sputtered like if it was out of fuel and shut off. Then turned right back on and didn't do it again.

[leonreno]

You need to buy a Mercury service manual for your motor if you plan on doing the diagnostics and repairs yourself.

[SilverFox579]

You need to buy a Mercury service manual for your motor if you plan on doing the diagnostics and repairs yourself.

^^^^

Contact Rhonda at European Marine to order a service manual, she will need your serial number - If you want to order or price Mercury Engine Parts or Accessories...

[LuistLTZ]

Today I found that a spark plug boot was almost completely unplugged. After putting it back on correctly it has been running normal. I'm hoping that's what it was. Still a good idea to get that manual though. Since I do all my own work if I can.

[EuropeanAM]