Merc 150 opti service parts

[jprivernut]

Model number: 1150P73HY/ Serial number: 1B903486
225 hours

Hey guys,
I'm looking or a list of parts with part numbers to do a service on this motor. Will be doing water pump kit and spark plugs. Will I need the gasket aligning pins and the "grommet depth seater"(Rubber part that sits on top of the pump housing on the shaft)? Also, LU gear oil, but already got that. What about any sockets or elbows that would make getting to the sparks easier? I've never taken the lower cowl off before. Thanks in advance.

[OldTimer57]

The seating tool comes in the water pump kit. You don't need the alignment pins. I took a wire tie that fit snugly into the WP housing bolt holes. Cut it into 3 pieces about 1" long and stuck 'em in the holes. The only hard part is getting the housing over the impeller since the impeller has to be deformed to fit. I found the wire tie parts held the gasket perfectly. Once you get the housing over the impeller, you can use the wire tie pieces to hold the gasket in place. Pull one out, insert the bolt, and then on to the next. Easy job. You CAN go to a local supplier and buy three bolts or studs with the correct threads if you don't like the alignment struggle. Didn't take me more than a minute to get the bolts in with the wire ties, however.

Probably easier to just remove lower cowl. 4 bolts (8mm? I think). The starboard side will come off easily if you unplug the tilt/trim switch on the cowl. The port side doesn't need to come off, just pull it away a bit for easier access to the plug. While there, remove and clean the compressor water strainer which is really tough to get to while the cowl is on. I find it easier to get it back on if I spray a little silicone on the lower gasket. It's a pretty snug fit where the cowl fits into the grove in that rubber gasket, silicon lets it slide in easily.

[SilverFox579]

The 2.5L is different than 3L you don't need any dowel pins for alignment because the water pump housing fits over studs held on with nuts not bolts. Also, there is no seating tool required because there is no seal that sits on top of the pump housing like on the 3L. Click this link and look at pic #5 to see - http://www.bassboatcentral.com/images/WP5.jpg

I always pull both lower cowls when I service my 150 Optimax as it's a prime opportunity to remove, check, and clean (if necessary) the strainer for the compressor inlet. Spark plug access is unrestricted and I always thread plugs in by hand before torquing to 20 ft lbs.

Here's a light bulb moment tip, leave shifter in neutral before dropping lower unit, making sure you DO NOT rotate driveshaft or engine. Now, after you have lower unit off, make an index mark on the driveshaft and housing before removing pump housing. After that, you can rotate driveshaft all you want and return it to the exact position when you removed it from engine. Slips right back in without having to rotate engine while trying to stab the lower unit. Be sure to lube new pump and housing with dish washing soap - not grease or oil.

Lots more info in the 2.5L forum (what your engine is), especially the FAQ at top of that forum (even more info in the 3L FAQ).

Recommended Annual Maintenance or Winterization for Optimax Engines

Compressor STRAINER Cleaning

Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations

For parts, visit European Marine's website check out link below

If you want to order or price Mercury Engine Parts or Accessories...

[jprivernut]

Thanks for the info and tips gentlemen! I have the Merc Compressor strainer relocation kit installed that allows easy access by remowing the top cowl. I highly recommend it for all Merc optis. It sits in a clear housing too. I've changed several pumps on 25 hp motors with no prob. I assume, with y'alls tips, I can easily tackle this by myself? One other question about dropping the lower unit: two nuts on port and starboard side, one beneath the zinc anode and the one in the very front? Is that all?

[g352nv]

The 2.5L is different than 3L you don't need any dowel pins for alignment because the water pump housing fits over studs held on with nuts not bolts. Also, there is no seating tool required because there is no seal that sits on top of the pump housing like on the 3L. Click this link and look at pic #5 to see - http://www.bassboatcentral.com/images/WP5.jpg

I always pull both lower cowls when I service my 150 Optimax as it's a prime opportunity to remove, check, and clean (if necessary) the strainer for the compressor inlet. Spark plug access is unrestricted and I always thread plugs in by hand before torquing to 20 ft lbs.

Here's a light bulb moment tip, leave shifter in neutral before dropping lower unit, making sure you DO NOT rotate driveshaft or engine. Now, after you have lower unit off, make an index mark on the driveshaft and housing before removing pump housing. After that, you can rotate driveshaft all you want and return it to the exact position when you removed it from engine. Slips right back in without having to rotate engine while trying to stab the lower unit. Be sure to lube new pump and housing with dish washing soap - not grease or oil.

Lots more info in the 2.5L forum (what your engine is), especially the FAQ at top of that forum (even more info in the 3L FAQ).

Recommended Annual Maintenance or Winterization for Optimax Engines

Compressor STRAINER Cleaning

Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations

For parts, visit European Marine's website check out link below

If you want to order or price Mercury Engine Parts or Accessories...

Wish I would of read this post last year when I did the water pump. What a pain the the butt lol.