Nor'Sea Engine Replacement
We Changed out an old Yanmar 2QM15
For a new Yanmar 2GM20F

Note:
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The engine on the Nor'Sea is under the cockpit sole, and between the aft cabin (or lazerett on aft cockpit models) and the main cabin. I have heard a lot of talk about cutting out the cockpit sole to make it easy to get to the motor. This does not sound like a bad idea and in truth, I thought about that for some time before I make actually did the job. BUT, I hate to cut holes in Guenevere! So I talked to Ed Zacko and Dean Wixom for advise and they both said it was easy to change out the motor. THEY WERE CORRECT!
 

This is a view of the forward end of the motor from the main cabin.
The first thing you need to do is to disconnect all external connections to the motor. Things like throttle cable, Tranny cable, electrical cables, Etc...

I also removed the alternator, but I do not think that must be done.
 

This is a view looking at the motor through the port aft cabin birth foot well. All the starter cables and tach sending wire was disconnected through here.
 
 

This is a view looking at the motor through the starboard aft cabin birth foot well.
 

This is a view of the aft end (tranny) from the aft cabin.
 

I also removed the fittings from the top of the fuel tank. As I knew I was going to replace the tank I did not bother to tape up the openings or protecting it in any way. Then remove the nuts from the engine mounts.

Now the trick Ed & Dean gave me. I bought a 2 X 8 board from Home Depot.
Place the board under the motor from the forward cabin as far back as you can (under the aft cabin floor). Smear the top of the board with grease. I used liquid dish soap to make it slippery.
Then I moved my boom vang and attached it from the forward compression post to the front of the motor.

Now you lift one end of the board just enough so the engine mounts clear the top of the mount bolts.
You can now use the vang to pull the engine forward into the main cabin just so the tranny is clear of the bulkhead and the motor is under the main hatch. Then remove the van as you will be using it to take the engine out of the boat.
 

This shows the engine compartment just after the engine was out.

Here is a photo of the starboard side of the engine compartment showing the two old engine mounts.

This shows the port side. Note the aft engine mount. The bolt is broken off. I did NOT know this was broken until I was removing the engine!
NOTE: If you will be changing to a new motor, you will be getting new motor mounts. When you remove the old mounts, use wood dowels epoxied into the old holes in the mount timbers. That way you can drill and tap new holes in the same area if you need to.

That's Gary Campbell & Bryan McIntyre helping me.

I then centered the boom and attached one end of the vang to it at a point just over the motor. The I then fastened the main halyard around the boom just where the vang was attached to it and made the free end fast at the mast cleat. In this way, the halyard was taking the strain, NOT the boom! I also attached a line with a block to the motor to control a bit of forward & aft movement.

We now swung the boom out over the dock and put the old motor on a dolly. And off it went to a shop for a rebuild.

Then the BAD news.
After a week I was given an estimate of the cost to rebuild it. As it turns out that cost was within $500 of the amount I was able to purchase a new motor for! I still had to think about that for a while as I was not sold on the fact that if I put in a freshwater cooled motor it was added parts and another type of fluid I would have to carry aboard. I know salt water cooled motors last a LONG time so that was not part of my thinking.

Well, as you know we decided to spend the extra money and get the new motor. And, I sold the old one for parts for $500.00, so it was even up.

When we bought the new motor, we also bought the manuals with it. The mounts of the new motor were not the same spacing as our old 2QM. So I had new spacers made to make the new mounts come out to the same width as the old ones. In that way we did not have to make any changes to the mounting timbers.

For the engine block mounts, it's the thickness that counts. You may need new longer bolts here.

For the tranny mounts, it's width that counts.

Here it is, installed and after we arrived in Mazatlan Mexico!