This is an interesting thread. One question I always ask is how do you guys prime the filter? I hate starting the engine dry to prime a big filter. Is there a way to prime it?

Yes, 2007 model. 100% stock. 128 hours....

PS: Thanks for the great advice and tips all!

Ok another reason why asked is because a bunch of the 1st HP 525 had the oil filter adapter with nothing in it nor the pipe plug on the side (18 mm pipe plug) The second gen of oil filter adapters had the 30 psi oil by pass relief valve added internally & and put that 18 mm pipe plug on the side of those oil filter adapters.

IF I RECALL CORRECTLY no oil will drain from that or if so it will be not that much if you were to remove that 18 mm pipe plug from the oil filter adapter. As I recall that was drilled and tap for adding the 30 psi oil by pass relief valve correctly / and position. I am going off memory here so Not 100 % about this -

Is this what you are asking about the 18 mm pipe plug on the side of oil filter adapter ???

let me see what I can find to pull up as far as parts list & pics also to help out what I am saying.

The first gen HP 525 had the 30 psi oil by pass relief valves installed in the oil t stat housing FYI. 2nd HP 525 gens had that 30 psi installed in the oil filter adapter. Hopefully I can find something to show that and the 18 mm side pipe plug.

I still pour motor oil in the upside down oil filter's but of course not full, I pour to saturate the filter media 100 % fully and about 10 to 20 % oil capacity only in the filter itself. You have to be quick to install the oil filter not to lose any of that oil - if you do enough you will not spill a drop. afterwards - I also bump the starter a couple of times (no engine start) to get the filter filled with oil the rest of the way and start to see oil pressure.

early to mid production HP 525

http://www.mercruiserparts.com/Show_...er%28Engine%29

Mid to late HP 525 you can see the difference in the oil filter adapter set up & oil T-stat housing plus other related parts compared to earlier years.

http://www.mercruiserparts.com/Show_...er%28Engine%29

Last post - sorry as I forgot to add that you can take a funnel and pour new motor oil down the connector that oil filter screws on to before you even install the oil filter as well. I still pour oil in the filter to saturate the media fully. Saturating the oil filter media is the longest time span for filling the oil filter of oil - get that part done and the oil filter will take not long at all to fill itself completely full of oil by bumping the starter (no engine start) or even starting the engine.

i use a center punch and poke a small hole at the very bottom of the filter that is really up top because it is mounted up side down,this breaks the suction and the oil drains cleanly down through the oil lines.i do this before i suck the oil out of the engine.i can,t tell you how many times i have done this and never hurt one of the engines to date.

This way works great and you don't spill a drop.