Please give me a logical solution check list. I am a diy guy, but not set up to pull engines out.

Engines were winterized last fall and fresh lake water was seen exiting each engine using the hand pump, and I also pulled the blue drain plugs. Engine temps while running are equal at 160F. Boat was stored in heated garage at 60F.

Each year I do the exact same pre-launch startup.

Before starting each engine:
1. Cooling system is de-pressurized and blue plugs are tightened.
2. House water is turned on (through a large diameter garden hose and exits a muff into the side intakes of the B1 outdrive) and it is splashing out the outdrive nose.
3. Through-hull exhaust is switched on.
4. I start the engine and within seconds water exits the exhaust tips.

Well today no water seems to be sucked into the port engine because none exited the exhaust tips (or out the prop area).

The port engine does not seem to be pulling water into the engine when started. (Starboard works fine and throws water out the exhaust tips as expected.)

Where is the most probable blockage? And how do I systematically solve and repair?

2004 496 mag. Never a single issue with either engine since day one; original owner.

Thank you.

Sounds to me that you may need a new sea water impeller which is on the lower portion of the engine starboard side. I just changed a couple on my 496 engines-- Not a fun job. Good luck!

The same exact problem I had today. Last spring I put new impellers in but did not replace the housing.

Thanks. I think you have correct diagnosis. Is there a way to be sure before I begin disassembly?

And should I do the starboard impeller as well, or will a new impeller be as likely to fail anyway?

Also, any chance you have a list of 'recommended' additional parts to replace, or just the impeller only.

So are you saying the housings are junk too, and should be replaced as a matched set with a new impeller?

If the housings have any grooves in them they're junk.....i changed my impeller and it won't flow enough water now...

Sunsational: If you haven't changed the impellers in 7 years you are long overdue. Of course, change both. You won't know the condition of the housings until you get them apart. I purchased Globe run dry impellers--allegedly better than Merc.......

Literature indicates the Globe impeller is likely superior. Globe lists part #2000 as the only impeller for a B1 with key. Besides a new o-ring seal, are there any other parts I should replace at the same time?

Is there a higher quality housing out there as well?

I might as well replace both on each engine and perhaps last another seven years!

Thanks for information.

Remakable you guys are talkin about this engine. Went out with a guy today with new 496 that he just received from Baja 4 weeks ago.

He started it up and water was pouring out of a verticle hole just below the two blue drain plugs. Is that hole supposed to be plugged ?? I have no knowledge of that engine.

Its the long weekend and no one is open to ask.

I'm guessing and only guessing that Fountain sent it up here winterized or something like that.

The hole where the water is pouring out doesnt appear to be threaded.

The pumps brass little sand, junk someone in arizona makes a nice rebiuld kit ,R&R industries with stainless plates ,great improvement .