Oil And filter Change for a 7.4L V8 Mercrusier Engine

[itskev90]

What type of oil should I use for my engine and the filter?

[biggerseagar]

What does your manual say? Different climates call for different weights of oil? Most use 25w-40, some use 30w or 40w. Having a service manual will help you make your choice.

I stick to the Mercury or Quicksilver brand. You figure you have spent all this money on your boat don't cheap out on it with oil or your filters.

Roger

[mmwjr]

I agree with Roger, yep 25W- 40 is the most common.

As far as I know all merc V6 and V8 use the same filter except the V6 without the remote filter kit while the V8 uses the same regardless is remote or not.

[itskev90]

Thanks guys,
I do not have a service manual. I bought this boat from a used boat yard. I didn't get any manuals.

[mmwjr]

Originally Posted by itskev90

Thanks guys,
I do not have a service manual. I bought this boat from a used boat yard. I didn't get any manuals.

Go to the Documents Tab of this site, Mercruiser manuals, there are 2 that cover the 7.4 also for the drive.

[shrew]

They boat doesn't come with an engine manual. It is engine specific and needs to be purchased separately. If you're going to do your own work, I suggest getting the engine manual and the drive manual.

As stated 25w40 oil. The oil filter should say "for Mercruiser Sterndrive and Inboards". I've never seen one specify v6 or v8 on it before.

[speedysprocket]

Related to this- anyone know if the 7.4L has flat tappet or roller lifters?

[mmwjr]

Originally Posted by speedysprocket

Related to this- anyone know if the 7.4L has flat tappet or roller lifters?

Not 100% sure but pretty sure it never came with roller lifters from Mercruiser.
Roller lifters showed up on the latter vortec small block engines.

[speedysprocket]

Originally Posted by mmwjr

Not 100% sure but pretty sure it never came with roller lifters from Mercruiser.

Roller lifters showed up on the latter vortec small block engines.

So do the mercruiser oils have the zinc additives (ZDDP) to help lubricate flat tappet cams? Not as big a deal in regular car or boat engines, but it wrecked a lot of racing cams when oil manufacturers took those additives out without telling anyone...

[mmwjr]

Originally Posted by speedysprocket

So do the mercruiser oils have the zinc additives (ZDDP) to help lubricate flat tappet cams? Not as big a deal in regular car or boat engines, but it wrecked a lot of racing cams when oil manufacturers took those additives out without telling anyone...

Good question, will have to do some reading, however I have been using their oil for over 10 years without any issues.