I’ve finally made the change to the water pump hose that I’d planned to do five years ago.  This was an inspiration based on the fact that the original water hose from the pump, which had been formed to fit around the front of the engine, was no longer being marketed anywhere. The hose I put on when the water pump was replaced back in 2005 was too stiff to completely avoid friction from the alternator belt pulley as it turned around the side of the engine. Here you can see how it butts up against the alternator.

top view of engine

And so as I was running the engine last week the hose finally wore through.

the hose compromised by the pulley

Still, it took 14 years for this hose to fail. Even the boatyard folks were impressed.

I’m lucky to be in a marina with its own boatyard. The folks here are competent and very accommodating. I wasn’t sure just what had gone wrong, and I walked over to talk to the manager, Dave Salmi. He agreed to send one of his engine men over to take a look. They did so right away, and determining that it was the hose, proceeded to look for a solution for a hose that wouldn’t rest against the alternator pulley.

Their initial solution was to run a hose down below the alternator which would require a change in the v-belt.

the original solution to the hose replacement wrapped around the side of the engine

They had a new v-belt on order to get this done when I remembered the pipe I’d bought in 2014, based on the engine on display at Cook Engine in Porltand.

the pipe to run hose around the engine the pipe on the M-20

I had to dig the pipe out of storage for them, explaining with pictures  what I had been hoping to do, and gratefully they didn’t flinch. They looked at the pictures I’d taken of the M-20 engine hose, and came up with a plan. They painted the pipe black, and installed it this way:

the new pipe installed at the water pump no elbow but a workable solution

the hose from the pipe to the side of the engine the new hose along the side of the engine

In addition, they replaced the pulley v-belt and provided a spare belt for future easy replacement. They pressure tested the finished work and it’s now complete.

I’ve run the engine up to temperature, and everything sounds and looks great. I’ve always loved this engine.