Water pump getting weak?

[JosMN]

Got the boat out over the wkend to get rdy for the season. She started right up on the muffs, but I noticed after running a minute or two that if I reved it a bit and backed off to idle the water would stop for a second or two, sputter a bit then start flowing again steady. I had the impellar changed last year. Could it be the water pump getting weak or is it just the fact I was running it on the muffs? Thanks for any help. Motor is a 1990 Merc/Mariner tiller.

[boatfixer]

Thing is, depending on the HP, your water pump is capable of pumping more than your hose can supply. Only real test would be to back it into the lake.

[JosMN]

It's a 60 hp.

[boatfixer]

Back it down a ramp and check it. A 60 can easily draw more than an average garden hose

[marine_man]

It is impossible to evaluate a water pump when running it on the hose. There's not enough flow, and at low idle, the water pressure can be enough to mask a failing / weak water pump. The only way to evaluate it is to put it in the lake, in a barrel or something along those lines.

marine_man

[JosMN]

Thanks guys! I will bring her out to a local lake and give her a try. I need to get out and do some fishing anyway!

[harvey lee]

I gave my 2 sets of ear muffs away.

Used them on my Merc and it shows no water being pumped. Put the motor in a tank of water or back it into the lake and it pumps well there.