Lessons learned from 1st Water Pump Change

General Boats and Motors
1

Finally put the Johnson 112 back together after replacing the water pump and learned a few lessons.

In no particular order, some things I would recommend:

  • If it has been awhile since the pump was changed, spray a good penetrating fluid on the gear case bolts. I would hate the thought of snapping off a bolt at the head.

-Buy a torque wrench rated in foot pounds for the gear case bolts. I bought one from Harbor Freight for $21.99 (less 20% with an online discount coupon). I feel a lot better knowing the bolts are tightened properly according to OMC specs.

  • I found it easier to install the impeller in the housing and then mount the unit rather than put the impeller in place and twist the housing using the drive shaft. I used grease to lube the impeller.

  • At least on Johnsons, make sure that you don’t move the steering linkage cable. If you do, carefully measure it before you re-bolt the gear case. If you don’t, and it is too high or low, off it will have to come until it is just right.

  • Buy a factory manual. Get online and watch the many video tutorials for changing a water pump. Go to the iboats site for lots of technical info. Do a search for picture tutorials (there’s a great one on this site, which is why I didn’t submit one).

  • Expect it to take several hours if it is your first time. Don’t get mad if (or when) you screw something up, and don’t sweat it - you now have the knowledge to perform needed maintenance all by yourself.

  • Get a second person to help you slide the gearcase back in place so the exhaust housing seals stay in place and the copper water tube lines up properly.

  • I bought the OMC kit. I found the prices to be pretty close to aftermarket prices, so I went with the factory stuff.

Sammie

2

I have the kit to do my 70 hp Yamaha. Just haven’t gotten the guts up to try it yet. Now I have convinced myself to wait until after shrimp season.

3

Don’t use petroleum based grease on the impeller; it will cause the rubber to deteriorate. You will be okay if it is run after installation. Not okay if you use grease and then store for winter.

Use silicone spray instead.

Iain Pelto
Edgewater 185CC “Jumpin’ Bean II”
Native Manta Ray 14

4

Plenty of time between now and shrimping season to tackle it, DFreedom. The worst part is getting up the courage. Once you start turning a wrench, it’s not bad at all.

I just used a little bit of marine grease, hairball. It is what the directions said to do. I think the trick is not to overdo it. A small amount will flush out pretty quickly without any harm done. I’m sure that silicone spray, teflon spray or dishwashing liquid would also do the trick.

Sammie

5

DFreedom,

Yamaha water pumps are way easier to change than OMC’s. I’ve got a Johnson 130 and had the same experience sammie had the first time I changed my water pump. Helped a friend change his Yamaha water pump last year and it was a piece of cake. You don’t have to mess with the shift shaft with your motor like you do on OMC’s.

6

Thanks, looks like I’ll be waiting until after shrimp season as I just left the boat down there at Carolina Boatyard.

7

Must be something about shrimping season. Started mine Friday 10 am just before leaving and it spit the water pump out. First time changing one but not as bad as I thought. In water 3:30pm and full cooler to boot.