Mercruiser 350 MAG 5.7 Oil Change

[THATDONFC]

Mercruiser 350 MAG 5.7 Oil Change

Hey guys, this is my first post here. I recently picked up a 20ft 1989 Larsen Lazer. I've been searching all over the net trying to figure out how to change the oil on this bad boy but I can't seem to figure it out.

I am a BMW mechanic so engines are not new to me. I don't have much experience with boat engines however.

From what I can see (and feel) there is no dipstick or drain plug on my engine. I'm wondering if maybe I just can't find it. Do any of you have experience with these engines?

Here's the info on my engine
Model: 4350100BS
Serial: OC621436

I think if I can't figure it out I may try and rig a fitting to attach to the oil filter port and crank the oil out with a push button starter (plugs removed).

Any other tips you may have as far as maintenance goes would be greatly appreciated.

-Chris

 

[m_steiger]

Most people use an oil extractor from Harbor Freight, I don't have one myself but they do make it a quick and clean job. You can also use a drill powered pump with tubing put down through the dipstick tube. I can assure you that you do have a dipstick unless it is missing and you most certainly have a drain plug on the engine. The drain plug is on the complete bottom of the deepest sump of the oil pan. When standing in front of the engine look to the immediate left of the harmonic balancer/pulley you should see a yellow dipstick handle or tube missing the dipstick. Shell Rotella 15w-40 is pretty good oil to run when your ready to fill it back up.

 

[THATDONFC]

Most people use an oil extractor from Harbor Freight, I don't have one myself but they do make it a quick and clean job. You can also use a drill powered pump with tubing put down through the dipstick tube. I can assure you that you do have a dipstick unless it is missing and you most certainly have a drain plug on the engine. The drain plug is on the complete bottom of the deepest sump of the oil pan. When standing in front of the engine look to the immediate left of the harmonic balancer/pulley you should see a yellow dipstick handle or tube missing the dipstick. Shell Rotella 15w-40 is pretty good oil to run when your ready to fill it back up.

Thanks for your quick reply!

I'll go ahead and look for it tomorrow. Guess I wasn't looking hard enough. It can be tough to get a good look with how little room there is.

 

[alldodge]

Here is all different kinds and it all is sucked out the dip stick tube. Don't change the oil by removing the filter

http://www.iboats.com/Marine-Oil-Change-Pumps/dm/view_id.246638

 

[THATDONFC]

That permanent drain hose looks awesome! I should be able to make a fitting like that at my shop. I think it would be easier to drain the oil through a hose attached to the drain hole. I'd need to drain the oil first before I can attach the hose though.

 

[Bt Doctur]

 

[bruceb58]

That permanent drain hose looks awesome! I should be able to make a fitting like that at my shop. I think it would be easier to drain the oil through a hose attached to the drain hole. I'd need to drain the oil first before I can attach the hose though.

That's the best way to do it. That's how Volvo's are set up. Pumping the oil out of the dipstick by putting a very small diameter tubedown the dipstick is a major pain.

 

[THATDONFC]

Does anyone know the thread diameter and pitch of the drain plug on my engine? I'm finding mixed answers. 1/2-20, M14-1.5 etc...