Oil Change

[The Pirate]

It seems as if the Merc oil change system, doesn't work very well. I just looked at how much oil came out in the spring and it can't be more than one qt.

This after running the boat from idle, to WOT, for around 30 mins. I thought I would get every last drop out with the oil hot.

Someone on here suggested the oil extraction thru the dipstick method. I might go that route next year.

But is there a reason the oil does not seem to drain out as well as one might think? Or some trick to improve it, that i don't see? Or, is the extractor the way to go?

Thx.

[mmwjr]

What is the system you used?

[MoonRiver]

I bought an extraction pump from West Marine a many years ago and I now swear by it. I'll never mess with a drain plug again. There are markings on the side of the container to help you determine if you got all the oil out. I bought the 2.9Q (smaller model) now that I have a big block engine I wish I had the 6.5L model.

[Gugi47]

Originally Posted by The Pirate

It seems as if the Merc oil change system, doesn't work very well. I just looked at how much oil came out in the spring and it can't be more than one qt.

This after running the boat from idle, to WOT, for around 30 mins. I thought I would get every last drop out with the oil hot.

Someone on here suggested the oil extraction thru the dipstick method. I might go that route next year.

But is there a reason the oil does not seem to drain out as well as one might think? Or some trick to improve it, that i don't see? Or, is the extractor the way to go?

Thx.

You can use a 14 Gage insulated industrial wire and pull it up on the tube to clear out the blockage when you draining the hot oil out. That works very well. Try it next time. Just remember, you have to take the oil cup off when you drain the engine oil. I tale the filter of to.
Good luck.

[RandR]

I use an oil extractor pump and insert the draw tube into the Mercruiser drain hose. It sucks out just about every drop and no mess.

[shrew]

I believe he is referring to the drain how that is connected the oil pan drain. It has a bronze threaded fitting on the end. It can be pulled through the garboard plug hole and used to drain the oil into a bucket outside the boat if the boat is blocked or on a trailer on land. This comes in some models. I had one in my 8.1.

My 8.1 drained (dripped) incredibly slowly. I ran the engine until the oil was warm, then drained it. It took hours to drain completely, and even then I felt like I only got about 6+ qts.

I went to an oil pump that pumps out the dipstick tube. That will drain 9 qts in about 5 minutes.

[RandR]

Yes Schew. That is exactly what I am talking about. Oil drain hose that is connected directly to the oil pan. Extracting through the dip sticks also works but you don't know exactly what crud is left in the bottom of the oilpan

[Calguy]

Mine has the oil change system but never used it.....I use the Top Sider MVP oil suck tank that you pump up and pressurize. Have a 2400 SCR it works great with the Mercruiser Horizon 350. Warm the engine, pressurize well and leave it for about an hour....sucks all the oil very easy out of the dip stick tube...

[The Pirate]

Thanks for the input. Good to see most peoples experience with this is similar. The idea of a blockage in the drain hose had not occurred to me. But seem like an extractor is the way to go. Thanks