Question about lube/oil for MercCruiser

[VVet69]

Hi,

I want going to start doing the lower unit and engine lube and oil changes myself on my Fisher pontoon (see info below). However, I did not get any manuals with the boat when purchased. Does anyone know where I can find the following:

- Oil specs and quantity for the engine oil (I will use a pump to remove the used oil before adding) and a good substitute for the Merc oil
- Oil Filter type and part number and a replacement type other than the Merc filter.
- Lower unit lube type and amount
- Info on how to drain/fill the lower unit.

Thanks in advance for any and all assistance.

[GXPWeasel]

IIRC from the days my dad had a bowrider with the 3.0 I/O in it, you can just use normal weight motor oil. I think the oil filter was the same as a 3.0 Litre GM engine as well. I wouldn't take my word as final on this though. See what others say.

The lower unit should just take a little over or under a quart of oil. I find my quicksilver lower unit oil at Walmart, with the nice little pump for it too.

[Bamaman]

I used to have the 140 hp (3.0 liter) Mercruiser in an Aristocraft I/O boat. I just used good quality 10W30 motor oil and auto oil filters. I'm thinking the crankcase holds 5 quarts with a filter change.

If you can get the filter number off your old filter, it can be cross referenced on Fram.com's conversion program. I think it's the same filter that old 1960's and 1970's I-6 cylinder and I-4 cylinder Chevy engines used. They're readily available everywhere.

Most lower units require just 1 quart of lower unit grease. I just get mine at WalMart in the sporting goods section--Pennzoil @ $5.50 per quart. A pump makes filling the lower unit so much easier than squeezing the bottle.

There are some tutorials about changing the lower unit grease around the internet. Let me see if I can give legible instructions.
1. Trim the motor as high as it will go, and then Tilt it to the highest level. Leave it a minute or so, and then Trim the lower unit to where the anticavitation plate is horizontal to the ground.
2. Put a clean drain tray underneath the lower unit to catch the old l/u grease. You want to be able to inspect the grease for water intrusion and/or metal shavings.
3. Remove the bottom plug and set aside.
4. Go to the vent plug which is higher up on the lower unit. Remove it and watch the fluid then drain into the pan.
5. When all the grease is drained, attach the hose to the bottom hole, and put the plunger end into the new bottle of l/u grease. Pump until clean lower unit grease steadily comes out of the vent hole.
6. Replace the top vent plug with a flat blade screwdriver--with a new gasket if applicable.
7. Remove the pump hose from the lower hole and replace the lower plug--with a gasket if applicable.
8. Inspect the old lower unit grease to see if there's any milkiness or obvious signs of water intrusion. If a lower unit is very old or if you've not owned the boat throughout its life, you should periodically have the lower unit pressure and vacuum tested to make sure the seals are not worn.

Then, you're good to go. It's just a quick and easy job.

I didn't properly maintain my lower unit on a Yamaha 115 hp 2 stroke, and had to end up buying a new Yamaha F150 motor. Unfortunately, that new motor came with a Bennington 24SSLX attached.

[tuned]

Adding to the knowledge in previous replies.

Lower unit oil- Any brand 80/90 gear oil will work fine. Not sure of quantity. Have about 4 quarts on hand and you will have some left over.

There is a new trick for changing engine oil, but you need the engine out to install the plumbing. Sucking the oil out the old-fashioned way never really gets the sludge out very well.
The next time you have the engine out, consider adding an oil drain kit, which consists of a hose attached to the drain on your oil pan. This hose gets fished out the bung hole of your bilge when you want to change oil (with boat on trailer). Works great.

[badmoonrising]

One thing to add, all of the above is good advice. Your 3.0 is a 2006, that year came with Mercruiser's quick drain system. Look in your bilge to see if there's a hose attached to the drain plug. You feed it out of the engine pod drain plug hole and drain into a bucket.

My 2006 Party Cruiser with the 3.0 Merc had it. The dealer didn't tell me and Tracker BURIED it. I had to attach a stainless cable to it so I could pull it out easily. The hose has a drain fitting on it.

[tuned]

One thing to add, all of the above is good advice. Your 3.0 is a 2006, that year came with Mercruiser's quick drain system. Look in your bilge to see if there's a hose attached to the drain plug. You feed it out of the engine pod drain plug hole and drain into a bucket.

My 2006 Party Cruiser with the 3.0 Merc had it. The dealer didn't tell me and Tracker BURIED it. I had to attach a stainless cable to it so I could pull it out easily. The hose has a drain fitting on it.

That is what I was talking about in my post as well. I new that some boats were coming out with it standard. Most guys figure out a way to attach the drain hose to their bung plug (using aircraft cable?). Mine is like that. I just pull the bung plug out of my tube and gently keep on pulling, the oil drain hose shows up and makes my oil change neat and easy.
Important tip for this system: I have read about guys that screw up their system by trailering with the bung plug out. The weight of the plug and oil drain hose fittings can pull the hose out so far that they flop around in the wind. When they get home, they have a messed up system. One guy said that he left an oil trail 50 miles long on the highway

[badmoonrising]

Lol yeah. I used a stainless fishing leader we use for bluefish and other fish that can cut through mono line out here, worked well.