I can tell you that I have been winterizing boats for too long. When I worked at a marina, we had a 5 gal pal with a 12volt pump on it that we pumped antifreeze into the engine through the water intake after the boat engine warmed up on fresh water being pumped in. Today, that is still what I do.

I can tell you that a boat that may not suck the water up the intake through the muffs may very well still move water through the engine when that boat is put in the water. When. Oat is in the water the impeller is usually flooded and it really just needs to push the water…. To talk simply about it. In fact I just winterized a boat that this was the case. What you will find is the impeller is old and stiff and the impeller blades are not compressing and expanding as they should to “draw” or “suck” water as the impeller rotates.

The bottom line, you need to replace the impeller as a start to make sure that is 100 percent. When you do that, the muffs will work properly.

Hope that helps,
Chris

2 Things.

1. you need to replace the impeller either way. I replace mine every year and we hardly use the boat. It’s cheap insurance to ensure you don’t lose a weekend.
2. You mentioned just wanting to get it winterized and deal with it later. Again, I’d refer to my solution of installing a fresh water flush real quick and then pumping antifreeze in.

Is there an easy way to check for "Bravoitis" if it's not pulling water?