Water Pump Change

'04 Merc 115 Four Stroke EFI

Anyone have an idea how difficult it is to change the water pump?

I did one on a 25HP Evinrude, years ago and it didn't seem that hard.

Watched some youtube videos and my biggest worry is the shift linkage I guess.

Any thoughts?

2 sets of hands makes it too easy. Put it in gear before you remove the lower unit. If it won't align turn the emergency switch to off and touch/bump the starter while one person puts pressure on the unit.

Jared.  I finally got it out today for a ride on the river with my wife and son.  It pumped just fine.  I ran the final few miles back to the launch a few RPM’s below redline.  When I brought it off plane, I ran back to feel the temp of the stream and it was luke warm.  The river was at 81 degrees so I think we’re golden.

BT,

You ever get on the water to test your pump?

Congrats Jared!  I haven’t gotten mine on the water yet.  Too much going on but may have time once we get the boy moved into his dorm in a few weeks.

FINALLY got my motor back together and got out today.

Shift linkage was being a um, not so nice. While mating the lower unit, I had my buddly slowly jockey the shifter and boom popped right up. Much easier two person job.

There was hesitation in the stream with the muffs,

When we got on the water, the thing was like a garden hose. Happy it worked out, finally.

BT,

I have had some old muffs as well. 

I got some new ones from Amazon for like 10 or 11 bucks and they "dual flow" meaning they feed from both sides.

Muffs

Check it on a lake , mine pisses way more than that and I know I need to change the pump . But I have 1984 Evinrude 2 smoker 

I got my project back together last weekend and tested it this evening.  I think I got it but would have been happier with a stronger piss stream from the motor.  My muffs are old and small so maybe it will pump more efficiently in the water.  I’m thinking that after replacing the entire pump, it’s either going to work or not work.  Here’s a video of it in idle.  Let me know what you think.

Pumping OK?

fltlndr,

That was my first thought.

I'll try the taps first. The less drilling/pounding I have to do on the alum, the better.

I appreciate the suggestion.

Jared you could also get a helicoil from an auto parts store.

Doesn't hurt to run the original size tap first, otherwise yes you will need to go up a size. Use plenty of oil on the tap.

Thanks Risto.

Good call on the tap, didn't think of that. I've been so discouraged with this damn boat, its really getting old.

Good thing is my dad left me at least a few hundred dollars in taps and dies.

Do I need to go one size up or just retap the threads? I am assuming one size up since it doesn't replace metal.

Here's a pic from my 125 Optimax.

Stripped hole - head to fleet farm and get yourself a tap & die kit for $40.

BT,

That's what I did, following the youtube video with 1.5 mil views, same motor.

I got a new impeller and gaskets. Dealer said housing looked fine. No grooves, nice and smooth.

Went to put it together tonight Using 1/4 drive, extension and deep socket. Stripped one of the holes. I didn't even torque on it.

Ugh...

So, the "fins" are bent when installed, obviously. 

Which way should they be orientated (left or right) when looking down on driveshaft?

Any suggestions on the stripped hole?

I haven’t gotten my motor put back together yet but the water pump is in the lower unit.  It doesn’t seem that hard but I almost installed mine backwards too.  Drive shaft spins clockwise so if you have the housing facing you and upside down, you gotta install so it spins counter clockwise.