Engine oil turns dark quickly

Discussion in 'Touring Models' started by larryjmiller, Jun 9, 2009.

  1. larryjmiller

    larryjmiller Junior Member

    Changed oil recently. Used Mobil 1 V twin. Everything went well. I have the electronic dip stick/thermometer but I still like to check it manually once in a while. After about 1000 miles the oil looks a little dark already. After a 1000 miles on my cars, the oil still looks new (light color). Anyone else notice this on their bike?

    No metal or strange smell, just darker color than when I put it in new.
  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    Also, your HD engine runs lots hotter than your water cooled car engine. Hence the emphasis here that folks use fit-for-purpose VTwin engine oil in their bike engines (20W50 for newer bikes). The higher heat also contributes to darkening the oil color.

    Once you have racked up a few miles on your engine, you will notice that the oil stays cleaner (lighter color) longer. Make sure you change your filter with each oil change, and I recommend using the HD specified filter for your engine.

  3. B-1B_Guy

    B-1B_Guy Junior Member

    The main reason is (as Hobbit indicated) that there is still oil in your lines when you pull the plug and you must scavenge to get it all out. here's an older link about an oil scavenger:

    Rogue Choppers Scavenger - Harley Davidson Community

    personally, I'm not willing to pay $150 for a scavenger....I'd build one first.
  4. Bud White

    Bud White Well-Known Member Retired Moderators

    Scavenger wont work on the 96's in the touring bikes.. and as said whats left over plus the heat turns it colors faster
  5. sanec1

    sanec1 Active Member

    I pulled the crank drain plug on my recently acquired 99 RK as the oil was pitch black. Should have checked that before buying. After doing this I read somewhere that you need to be cautious when doing this as the threads can strip. Anyone care to comment on whether this is practical?
  6. gs34

    gs34 Junior Member

    You need always be cautious when removing and reinstalling any drain plug. clean it and the threaded hole well, and inspect the threads.
    Apply some sealant, or thread tape if you prefer and carefully reinstall.
    Caution! do not overtighten. That is where the problems start.
    If it is a plug with an O-ring and straight threads, follow the torque spec in the shop manual. If it is a NTP plug, make it only tight enough to insure it does not leak. Remember, with tapered pipe fittings, it is possible to tighten them a little more every time, which moves them further in on the threads, making the hole a little larger each time. Eventually, you will run out of thread, and will be unable to tighten the plug. That is why you only want to make it tight enough to be secure, and not leak.