Leaded Fuel Only?

Discussion in 'Bubba's Outboards' started by jdw123, Jul 12, 2008.

  1. jdw123

    jdw123 New Member

    Messages:
    60
    State:
    texas
    i stopped and looked at an older boat for sale with an inboard engine on it. on the engine it said leaded fuel only. if you put unleaded in it will it ruin the engine? where are you supposed to get leaded fuel at?
     
  2. jdw123

    jdw123 New Member

    Messages:
    60
    State:
    texas
    nobody knows?
     

  3. justwannano

    justwannano Active Member

    Messages:
    1,003
    State:
    SE Iowa
    If you are concerned "Wynn" (sells/sold ?) a product called "valve guard lead substitute".
    FWIW I still have a bottle of it from years ago.
    Never needed it.
    have a good one
    just
     
  4. slimdaddy

    slimdaddy Well-Known Member

    Messages:
    2,603
    State:
    Nelsonville, Oh
    Name:
    Keith
    no i dont think it will hurt it only if theres a cataletic converter cause it will plug them up you dont have a chioce cause you cant get leaded no more
     
  5. BailBonds

    BailBonds New Member

    Messages:
    282
    State:
    Indiana
    The removal of lead resulted in the valve seats needing to be hardened. I've read more than one study that unless you were running an engine under extreme conditions it made little or no difference running unleaded with the softer valve seats. The real problem as stated was clogging up converters. They do still sell the lead additive as auto parts places.
     
  6. psychomekanik

    psychomekanik New Member

    Messages:
    2,534
    State:
    Illinois
    Leaded gas acts as a lubricant for softer valve seats. with unleaded fuel the valves will stick and possibly burn. don't believe "case studies" I've seen it myself dozens of times on older automotive engines, where they switched to unleaded and burnt a valve or bent a pushrod because it stuck. remove the head and have hardened seats installed. If it has a lot of hours on it, it probably needs a valve job by now anyway. or use a lead substitute. I would'nt run it without doing one of the 2. especially in a marine application.
     
  7. tufffish

    tufffish New Member

    Messages:
    1,196
    State:
    Texas
    we use the lead additive in some older tractors. we have some tractors that are at least 30 years old and 2 that are more than 40 years old.
     
  8. BailBonds

    BailBonds New Member

    Messages:
    282
    State:
    Indiana
    Thanks for the heads up on leaded gas. I'd never heard of a valve sticking because of using unleaded gas in lead heads. I've only seen them stick in the guides having nothing to do with lead, not a valve sticking to a seat because it was soft. I work on mainly older motorcycles pre 70's. One of my own bikes a 67 Triumph (bought it new) ran on unleaded gas with original seats since 1980 until 2 years ago. I did press in the harder seats then. So marine applications I'm sure are much different. Thanks again.