Merc 75hp impeller / water pump probs ?

[Bigbartguy]

Pulled away from my dock last weekend and the motor was extremely loud. No alarms going off, but I looked and the motor was not shooting water out of it. I shut it down immediately. No weeds on the intake grate. My area is very weedy/silty. I pulled the lower unit and the impeller looked good but I'm replacing anyway.

Since 4th of July is looming, I've only got this weekend to fix it……or else the annual 10 day family vacation is going to be cancelled (no sense going if we have no boat to use!)

I brought the lower unit home with me, so I've bought impeller and gasket and will be installing in lower unit tonight. Thermostat should be good, since it should be shooting water whether the thermo is open or not.

Can anyone give me any advice on other things to check when I get back up to the cabin? How do typically clear the output line (small wire? Compressed air?). Anything else I should be prepared to look at? I don’t have internet access while up there so I'm trying to do my research ahead of time, since I'm only getting 1 shot at this.

Any help would be appreciated, I've never had this issue before! Thanks everyone

[eurolarva]

Can you post a make and model number? When you install the impeller you want to know the direction for the drive shaft. If it spins clockwise you want to slowly turn it that direction when you put the pump over it. If you turn it the wrong way the vanes will not seat correctly.

[marine_man]

Can you explain "extremely loud"?

Usually a non-pumping water pump won't have any affect on motor noise, unless the engine's already burnt up.

marine_man

[Bigbartguy]

sorry, it's a 2002 75hp Merc - model 1075412AD.

I dont know if loud is the right word (I'm certainly hoping it's not) but something didnt sound right?

I'll be sure and put the impeller in correctly and have instructions. I figure it wont hurt to replace it even if it's just a plugged line.

I've got a service manual on order but unsure if I'll have it time for the weekend.

I'm just wondering if there's something else I should be prepared to look/do?

[marine_man]

Well, there's no harm in trying to replace the water pump, but if you do that and things still aren't sounding right it'd be time for a compression check.

Any idea how long it hasn't been pumping water?

marine_man

[Bigbartguy]

4-5 min at idle speed I would guess?

[marine_man]

It worked last time?

marine_man

[Bigbartguy]

yep it was spitting water. I check it pretty often because of my dock area. Cut across an area that I dont usually go and didnt seem like it was running right (from weeds? I dont know). I looked, no water, and I shut it down.

Pulled up the motor - maybe 1 or 2 weeds going into the grate, that was it.

[marine_man]

Well, hopefully the waterpump will take care of it!

marine_man

[Bigbartguy]

spoke w/ Marina this morning. They said to install impeller, put motor in the water and fire it up. Take air compressor and shoot air into the 'pee' hole in attempt to clear. He said very often this will clear it.

if not, it becomes a very big deal...pull powerhead and get in there and manually clear the line.

[marine_man]

I'd pull the telltale hose off and see if you can clear whatever obstruction there is there... since your motor is a 2007 I wouldn't think your impeller would be that bad yet unless you run this motor a lot.

marine_man