You may have already seen our video on How to Change Lower Unit Oil on a Boat, and today we're at Norfolk Marine to see how you change the engine oil on a 4-stroke. Let's get started.



Chris Breeden, Service Manager and Yamaha Master Tech: Okay, we've got the top off and we're in the shop, we made sure we got the engine is up to operating temperature so we can get all the oil out of it. Next step, we're going to remove the dip-stick, set it aside, grab the tube (of the oil pump)...

Lenny: Hey, was a minute Chris, why don't you just use the drain down here instead of using an extraction pump?

Chris: Well, you can use the drain, but the main thing is it's very messy, and if you're doing service over the water it's just not an option, you have to take it out through the dipstick so you don't make a mess.

Lenny: Good point.

Chris: Now you just pump it until the oil's out. Now, we'll put a rag under the filter to try and keep the mess down, take your filter pliers, break the filter loose, and remove it.

Chris: Okay, now you want to put a little oil or grease on the new O-ring, and spin the filter on hand-tight. The final step is going to be filling the motor with oil and checking the level. We have the oil changed and checked it and it's at the proper level, now we're ready to roll.

Lenny: Hey, let me ask you something. An oil change is not an incredibly complex procedure, but if you mess it up, you pay big time, don't you?

Chris: Yes, the consequences are pretty severe.

Lenny: So how does someone know if they should try this job or not?

Chris: Well, if they have a mechanical background and it's something they feel comfortable with, and they've done it on other things, they probably would be OK.

Lenny: Otherwise, we hope you take it in.

Written by: Lenny Rudow
With over two decades of experience in marine journalism, Lenny Rudow has contributed to publications including YachtWorld,, Boating Magazine, Marlin Magazine, Boating World, Saltwater Sportsman, Texas Fish & Game, and many others. Lenny is a graduate of the Westlawn School of Yacht Design, and he has won numerous BWI and OWAA writing awards.