Water pump and impeller change in Johnson 130 V4

Firstly, thank to JohnRudeTips for their article on changing a Johnson water pump.  Here is the page: http://www.bassboatcentral.com/johnrudetips.htm

This is meant as a supplement since the 1996 and older V4 seems to be a rare engine when it comes to help.

Raise the engine up and set the rest stop.

Shift into reverse so that the shift rod is in its lowest position. Once in reverse, go to the port side of the engine and look through the hoses towards the middle, low behind the carbs, practically against the block of the engine and find the bolt pictured here. This is the shift rod bolt that needs to be removed.

It’s a 3/8 bolt if I remember correctly. A long 1/4 inch ratchet extension and an elbow joint make this an easy task. Also, get a telescoping magnet to pick up the bolt after removal.

That picture shows the bolt on the end of the magnet. Note that only half of the bolt is threaded. That should give you some indication of why it won’t unscrew all the way.  use the magnet to pull it out.

Unbolt the torque plate from the lower unit as well as the bolt revealed after removing the torque plate and the one next to it. There are also four bolts – two on each side of the lower unit that we must remove. The lower unit is heavy, so if you can’t handle 40-50 pounds easily, get someone to help you pull it out. The shift rod adds a little resistance when removing the lower unit. Pull, but be ready for it to pop out once released. Also be careful not to let the exhaust tube fall. Here is the bottom after removing the lower unit.

Here is a picture of the shift rod to understand more of what you’re trying to pull out and remove the bolt from:

Unbolt the water pumps four bolts and pull it up off of the driveshaft.  If the impeller is locked, turn the water pump while pulling up in order to unlock the key from the impeller.

Follow the instructions on the water pump kit.  My only problem was finding OMC Gasket Sealer.  I checked some forums online and deduced that using Permatex #3 works just as well.  O’Reilly in my area ordered it for me next day and cost $3.99.

Here is the permatex on the water pump case:

Once everything is together, continue with the pump instructions and bolt it in.

While I had the lower unit off, I decided to also change the oil.  Take off the top level screw first:

Then drain the oil by removing the bottom drain screw:

After all the oil is drained (takes about half an hour), screw the oil pump into the bottom drain screw hole and pump the oil in until it just comes out of the top level screw hole.  Screw the top level screw back into place.  Unscrew the oil pump tube from the drain hole and quickly insert the bottom drain screw.  You’ll lose a little bit of oil, but that’s okay. Now, the job’s done.  Time to put it all back together and enjoy.

The hardest part for me to get the lower unit back in was lining up the shift rod into the part where the bolt goes back in.  Ensure that the exhaust tube and the tube that goes into the water pump line up correctly and then get the unit as far up as possible.  Put at least one side bolt in to hold it up.  You also may need to turn the prop in order to get the drive shaft splines to match up.

Once up, you can get a long flat head screwdriver just under the top casing to wiggle the shift rod up some more.  The lower unit should come up a little easier after that and you can use the bolts to raise it up the rest of the way. Once up, put the shift rod bolt in the socket attached to the elbow and insert into the “holding plate”.  The rod didn’t line up for me, so I had someone shift slowly from reverse to neutral while I put pressure on the bolt.  It snapped right in at about neutral.

After all the bolts are back in and the shift rod is fastened and tight, the job is done.   No biggie, right?