Results 1 to 3 of 3
  1. #1
    Member
    Join Date
    Feb 2010
    Location
    Oak Park, California
    Posts
    26

    Mercury Black Max 175 V6 - Poppet Valve Question

    I have a 1989 Mercury Black Max 175 hp V6 - Serial Number 0B383305. How can I tell if the Poppet Valve is opening and closing properly?

  2. Member
    Join Date
    Mar 2012
    Location
    Pelham, GA
    Posts
    2,004
    #2
    Do you have a pressure gauge? If so, you should see it stutter as it opens around 1500 rpms or 8-9 psi, otherwise would be hard to tell other than overheating or staying to cold.
    Mercury 2002 200hp Carbed Saltwater
    OT566776
    2002 Cape Horn 22' Bay

  3. Member
    Join Date
    Feb 2010
    Location
    Oak Park, California
    Posts
    26
    #3
    I do have a Water Pressure Guage on the dash of my bass boat. Now that you mentioned it, I have seen the guage needle stutter momentarily when accelerating from starting out to getting up on plane. I’ve been wondering why that happens. So it sounds like that’s a good indicator. I replaced the Poppet Valve assembly last year. I have been battling overheating issues with a new (rebuilt lower unit installed last year) which I discovered had gear oil getting up into the water pump assembly. (See related post in above forum). I cleaned all that up and replaced all water pump parts. Put the lower unit back in yesterday. Still need to get up to the lake for a test run.

    Thank you for responding and info!