Seems like I go through one of these under the cowling oil tank assemblies every 2 years or so. First one was under warranty so I didn't mind, second one was $400 bucks installed, hurt a little more. I'm considering replacing it myself this time and getting a cheap part. My preference will always be an OEM part from Mercruiser but I'm thinking since they fail so frequently anyway...Might as well save a few bucks. Has anybody tried one of the cheap oil tanks from Amazon/Ebay on an Optimax Pro XS??

I have been thinking about it till my oem part comes if it ever does been waiting since mid may

Buddy just had his fail, they said 8 month backorder....

You will NEED TO HAVE a Computer Diagnostic System (Oil Pump Prime Sequence) performed. It is VERY VERY VERY important to have done so there is ZERO air in the line. Good way to blow a power head. A shop has to perform that function. They will actually put it on a computer when they perform the procedure. It only takes about 5 minutes but getting them to do it while you wait can be an issue. There is, however, an “in-field” “diy gear shifter” method but is not recommended. This method basically puts your motor back in to “break in” mode for 2 hours which double oils the system. This can also lead to fouled plugs. There is also a concern for the compressor using this method. I know it’s a PITA but having a shop do it could save you thousands in the long run.

When y’all say your oil reservoir “went out” what do you mean? I actually need one now for my 250 Pro XS because I got complacent and let my big bilge oil reservoir run out and when the onboard oil reservoir dropped to about 3/4 full I got a warning buzzer. After filling the remote tank I had to “purge” the air from the tank so I could so I could get the warning bell to stop. With motor running and cowling off I opened the cap on top of the reservoir until the tank filled. When.tightening the cap it would not seal and small leak occurred at cap. There’s an o-ring gasket on top of the cap and I was careful(I thought) not to over tighten the cap. “FINGER TIGHT”. Now I need a new one. I was told by Charlie’s Outboard Alvarado and Fun & Sun Cleburne they have been on back order all through Covid and could be indefinitely(years?) for OEM. Mike2718: are you saying this “Oil Pump Prime Sequence” would need to be done in my case where the tank was never run dry or emptied? That’s what happened to mine. Other then me over tightening the cap what “problems” are y’all having causing a plastic oil tank to “FAIL”? Thanks, Neil.

I orders a oil tank assembly on 4-7-2022 still waiting.

In my case, oil is spewing out of the tank and coming seeping out of the cowling. Based on the information I've heard here, I might just try to epoxy the spot where the leak is.

You only have to do the Oil Pump Prime Sequence if you remove the engine mounted oil tank and install a new one or remove any of the oil intake hoses. If the tank just got low, you should bleed that tank. It should always be full. You need to trim motor up AND turn the motor so that tank is tilted to the point when you take off the cap, the “air pocket” is directly under the cap. Put you cap on loosely and start the motor. Once oil starts coming out, tighten the cap and you should be good. It’s very easy and typically won’t take too long for it to start overflowing unless it was very low. In that case, fill it up as much as you can using a turkey baster or something similar til it’s almost full, then run the motor and it will start to overflow, then tighten the cap but it looks like you have that part down. I have found if you don’t tilt and turn the motor, you will never get 100% of the air out.

I have used 5200 in the past to do the same thing on a Power Pole oil tank. Never had another issue with it. I prefer 5200 in that situation because it is permanent and it does have “some flex” so it can “give & take” with any tank “expansion.” Epoxy may work just as well too but it is very stiff and I would be afraid it would crack over time.

Good info! TY Mike

JB Weld Plastic Weld..... or possibly Marine Weld

Sorry but what is 5200?

Pretty sure they're referring to this:

Wow. Haven't heard that there was an issue with these. And really surprised so many on here are having it.

thank you!!