I talked with the mechanic of a boat I am looking to buy. The boat has a 525 efi that does not get ran much, but he mentioned the engine is using "some oil" said it has always done it, he swapped from Merc 20w-40 to merc 20w- 50 this last oil change due to some bulletin. the engine has 380ish hours on it I have someone that I am lining up to rebuild the top end in one of the next 2 seasons. ( I wont be using the boat a ton due to an new baby later this year). Is it normal for these engines to consume a little oil? or if this a red flag I should be worried about?

Thanks,
Andrew

How much is "some"?

Is this a sealed engine ??

He was not sure to be exact because he does not know how much the boat is ran between checks, but says he adds some every once in a while. Again.. I know its not specific.

It should be. Never been rebuilt or taken out of the boat to my knowledge.

That is if my understanding of sealed engines is correct. They come sealed from the factory and unless taken apart and reassembled they should be sealed correct?

Ok, the reason I asked is some guys rebuild them and dont put in the lifter pan and the engine will suck up oil through the pcv and dump it into the upper intake plenum

I see your in Topeka, Luke Sebert is out by the Heartland park, great guy and does excellent work

Underpsi asked the right question...quantify some...?

it is well known that blue motors “use” oil even if there is nothing wrong with the motor. This is due to the low tension rings used on forged pistons. I’d say using a qt every 10 hours is about normal. Some use more and some use less.

if you are needing to add substantially more than this...I.e. 1 qt every weekend. Probably need to do a health check or figure out what’s going on.

good luck

This sounds more like what is happening. I plan on doing a compression and leak down test when we go Sea trial the boat to see if there are any issues there.

I have heard that name around. Ill have to check him out.

F-2, let me know if you ever plan another trip to Perry, I would love to check out the CIg. That is a dream/retirement boat for me.

I miss spelled it, Siebert Performance ( Luke ) he did the machining on the 500 EFI's I rebuilt,