If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Follow us on Facebook Follow us on Twitter
Results 1 to 8 of 8
  1. #1
    Join Date
    Jul 2004

    Cool 525 Oil and Filter

    Second request... Anyone know of a good quality after market oil filter for the Merc 525's? Also, the recommended oil is 25w 40, and I don't see that at the average auto parts store. I'm getting ready for my first oil change and want to get the parts rounded up.

    How about fuel filters?

    Would it be a good or bad idea to use good quality after market parts?


  2. #2
    Registered Biggus's Avatar
    My Boats:
    02 Cigarette Mystique T/S
    Join Date
    Apr 2001
    Naples, Maine

    Re: 525 Oil and Filter

    Fram HP-4 is a great filter.

    I'd run a good quality straight 40 weight oil and change it every 15-20 hrs.

    Not sure on the plugs. I've had great results with NGK UR-5's. Ran them all season.

  3. #3
    My Boats:
    2008 all of the above
    Join Date
    Nov 2003
    Fife washingtont

    Re: 525 Oil and Filter

    The Merc racing oil filter is your best bet. I use these on a lot of custom motors. The key is how often you change the oil. Same goes with the fuel filters. You may not even find after market filters as far as the in-lines go. Plus if you have any warranty issues regarding the internals of the engine the best filters to have on at that time would be Mercury. I always recommend using the merc oil also when dealing with warrantied motors. The key with mercs 25w-40 is that this is a true 25w oil mixed with a 40w motor oil. So that part will stay constant. Some manufacturers advertise multi-viscosity. Such as a 10w-40. They start with a 10w oil then add chemicals to make it a 40w. The problem is if that oil ever gets overheated or goes past it's life span you basically end up with a 10w oil. Stick with the straight weights or make sure you know about the multiviscosity you are buying. Best bet is use the merc 25w40. You probably will not find the 525efi sold at auto parts stores either.

  4. #4
    Registered masher44's Avatar
    Join Date
    Sep 2004

    Re: 525 Oil and Filter

    You need to search for a thread called "Mobil 1 20W 50 V- Twin. After reading that you will use Mobil 1 filters & Mobil 1 Red Cap 15W -50 or 20w-50 V Twin.
    I run M1 everything in my 525... M1-301 filter and V-Twin 20w-50 in the engine.... also redline heavy in the outdrive. Check out that thread.. it is from a month or so ago and it is amazing how much you will learn. Specifically see the Posts by Hydrocruiser.... he knows his chit!

  5. #5
    Forum Regulator VIP Member Sydwayz's Avatar
    My Boats:
    17' Speedliner Cat & O.P.B.
    Join Date
    May 2001

    Re: 525 Oil and Filter

    Lots of info on here. Do a search for Oil Filter Study here in the tech section. You will NEVER buy a Fram again. I had one damn near kill me years ago by exploding on my crotch-rocket.

    Only Oil Filter I buy is Napa/Wix Racing; for my cars, boat motors, and trucks.
    One read of the above mentioned study will convince you.

    As for oil. Mobil1 15w50 period.

  6. #6
    Gold Member Gold Member Hydrocruiser's Avatar
    Join Date
    May 2004

    Arrow Re: 525 Oil and Filter

    These filters fit all V-8 Mercs I have been told..

    Oil Filter f/ most Mercruisers
    FYI:The thread type on the filter is 13/16-16.
    Fram: PH5, HP4, DG5, PH13 (no anti drainback) Pureolator: L34631
    Purolator Pure One: PL34631
    AC: PF1218, PF932
    Motorcraft: FL-12A
    NAPA: 1060, 1060gold
    Wix: 51060
    Wix Racing: 51060R, 51061R R= Racing
    K&N: HP3002
    Baldwin: B1428 (Top Rated)
    Amsoil: SDF-24
    Hastings: LF279
    Fleetguard: LF3679
    Mercruiser: 35-802885Q
    Mobil 1: M1-302 or M1-111
    Kendall: K31
    Penzoil: PZ45
    Quaker State: QS5
    Shell: S63, SH38
    Texaco: T38, T38B
    Warner: PH1218
    STP: S01218
    Valvoline: V056
    Support our President; Support our Troops.

  7. #7
    Gold Member Gold Member Hydrocruiser's Avatar
    Join Date
    May 2004

    Arrow Re: 525 Oil and Filter

    I will re-post this in case it gets lost..

    was asked to provide a simple summary of the "oil thread". Both my findings and those of others so here goes:

    1.) Synthetic "PAO based" oil is always going to be better than any conventional oil.
    Mobil-1/Redline & Amsoil are the three true PAO's I am aware of. Some "synthetics" are derived from lower grade base stocks and some are derived from linseed oils even. I want true hydro-cracked high base stock PAOS if I am to use synthetic oil. period.

    2.) Additives matter a lot. Soon with "CH-4" API mandates of much lower doses of ZDDP which is zinc and phosphorous based anti-wear additives; will be reduced; using a "Racing" or "Severe Duty" product avoids the need to conform to these new guidelines. Just look at the label if it says API CH-4 compliant it is the newer formulation. Now Mobil-1 has gone to a 3 additive package to compensate and it works fine; Redline and Amsoil will have new additive packages I understand. So it's not that big a deal unless you race. If you race and want the high ZDDP levels then buy Mobil-1 V-Twin or Amsoil Severe Duty or Redline Racing Products as they will be for "off road use" and will not be affected. They will not carry the true API "starburst" seal.

    3.) I was asked which oils I like best after months of research: take your pick they are all great:

    -Redline 15W-40
    -Mobil-1 15W-50
    -Mobil-1 20W-50
    -Redline 20W-50
    -Redline 20W-60
    -Amsoil 20W-50 Series 3000
    -Royal Purple 20W-50 (dosen't appear to be a PAO but good quality oil)

    Redline 20W-60 and Mobil-1 20W-50 are the toughest in the pack...if you need them...

    4.) What oil filters do I like best? hands down favorite.
    -Amsoil Heavy Duty
    -If you have to go cheaper then A/C is the best $ 5.99 filter out there.

    5.) Use additives?
    Nothing needs to be added usually to these synthetic products though Lucas makes very good additives they say. Their products cause oil to "pump up into" lifters etc. from what I read. I don't know much more about additives.

    6. Frequency of oil changes:

    -I am fine personally with these products and 50 hrs. Some engines and driving habits may facilitate more frequent changes.

    7.) Out Drive Lubes:

    -Redline Heavy Shockproof
    -Royal Purple
    -Amsoil GL-5
    -Merc HP (Semi-synthetic)

    I don't think you will go wrong with any of the above products. If you like conventionals I would personally use only Merc 25W-40 or a straight 30wt. Even the best multi-vis conventional oils shear down way too much. The Merc product is a blend of straight weight products. Would I personally use a 20W-50 conventional product? I would not; but Kendall and Castrol would be two 20W-50's that would be the best in the group. They still do not hold up as well after testing as a straight weight conventional.

    Now a synthetic oil can handle heat and shear up to 10x better; so a multi-vis PAO synthetic is fine.

    Hope that helps...see ya.
    Support our President; Support our Troops.

  8. #8
    Join Date
    Jul 2004

    Cool Re: 525 Oil and Filter

    I love this forum!!! You guys really got into this one!

    Thanks to all... especially Hydrocruiser. I got more info than I hoped for.

    Now, let's get out an run'em!


Similar Threads

  1. oil filter for 525 efi
    By gsmith9898 in forum General Q & A
    Replies: 17
    Last Post: 08-16-2012, 10:14 AM
  2. Replies: 21
    Last Post: 02-08-2011, 11:24 AM
  3. 496 oil temp senders remote oil filter
    By Velocity Vector in forum General Q & A
    Replies: 0
    Last Post: 04-03-2008, 01:45 PM
  4. 525 efi water/fuel filter part #
    By gsmith9898 in forum General Q & A
    Replies: 3
    Last Post: 06-26-2006, 07:42 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
OSO Sponsor
OSO Advertisers

OSO Directory
All times are GMT -5. The time now is 06:18 PM.
Powered by vBulletin® Version 4.2.0
Copyright © 2017 vBulletin Solutions, Inc. All rights reserved.
Search Engine Optimization by vBSEO 3.6.1
Original Poster In Postbit provided by Original Poster In Postbit v1.0.0 (Free) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
Copyright 2011 OffShoreOnly. All rights reserved.