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  1. #1
    Member
    Join Date
    Jul 2020
    Location
    Illinois
    Posts
    1

    Fuel on driveshaft splines

    Good morning.

    About three weeks ago, I inherited a 2002 Nitro NX 750 Dc with a 90 Mercury outboard (0T586609) that sat winterized for 2 years. I am fairly mechanically inclined, but a total novice when it comes to outboards and engine repair.

    After some general cleanup, I attempted to start the motor with a hose flush. The motor would turn over strongly, catch, and run for 1-10 seconds. The tell tale was ejecting water during this time. After about a dozen attempts the tell tale stopped ejecting, so I immediately stopped trying to start the motor and let it flush for another 5-10 minutes.

    The first thing I did was to change out the water pump and started the recommended 100 hr maintenance. However, once I removed the lower unit, I noticed a black, oily substance that smelled of fuel on the top of the drive shaft on the splines. I ended up cleaning everything up and completing the pump change which actually had a blown gasket between the pump housing and plate.

    Am I correct to assume that the fuel on the drive shaft splines is a bad thing?
    Will I cause catastrophic harm if I try to start the motor again.

    At this point, I have just reassembled everything and let it sit. I think I may be approaching the point of letting a pro take a look and just calling it a day.

    Thanks

  2. Member
    Join Date
    Jun 2013
    Location
    LONGVIEW TEXAS
    Posts
    13,938
    #2
    possible lowewr crank seals leaking , could be robbing oil mix from lower bearing
    .................................................. ...the scariest thing in life is the unknown ...................................

  3. Member
    Join Date
    Jan 2012
    Location
    Houston
    Posts
    1,165
    #3
    Agreed on lower crank seal. Yank the powerhead and repc from the bottom. Not too bad of a job
    90 Shadow 20' Mod V w/ 200 Merc - Total resto and loving it!
    Here's my build from cap-off to boat in the water.
    http://www.bbcboards.net/showthread.php?t=336645