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running engine dry after use

Discussion in 'Boats and Motors' started by Lewzer, Jun 2, 2005.

  1. Lewzer

    Lewzer Powderfinger

    Can running the engine dry after use cause problems with seals to dry out?
    I pull the gas line off the motor in the fall to remove gas/oil from the engine to store it for the winter.
    In the summer if I can't go out for 2-4 weeks I'll let the engine run dry.
    Can doing this cause any problems. The motor is a 1999 Mercury 25hp
    2 stroke.
  2. I am wondering whether you asked this because you are having problems that you are suspecting are related?

    I am not the most mechanically inclined but I don't see the problem in it. I have various 2 cycle and 4 cycle engines that run out of gas very regularly which if I am understanding you correctly is really what you are doing. I never have had any problems with a motor that I related to running it out. I would be interested though to hear others opinions as well.

  3. Lewzer

    Lewzer Powderfinger

    Nope. I am having no problems whatsoever.
    I hook up the line, squeeze the bulb a few times, pull the choke and it starts right up.
    Basically you hear of all the problems of the diaphrams or carb parts getting laquered up from the gas/oil mixture if it has been sitting too long. So I try to avoid leaving the motor sit too long with the gas/oil mixture in the motor.
    Was just thinking wether this is a bad idea and whether it could cause problems in the future. I will keep running it dry for winter storage since that is for 3 months. In the summer a couple weeks of storage should not cause a problem.
    I just threw the question out there for a knowledgable person's opinion.
  4. I was always taught that you SHOULD disconnect the fuel line and run the motor dry, for the exact reasons you say. Most of the time that's what I do with my 45hp Merc, and I used to do it with a 9.9 Force and a 25 horse Evinrude back into the 80s. It seemed to avoid, rather than produce, problems for me...

    Dr Chip
  5. On a 2 cyl engine they run real lean right before it runs out of gas.No lube!
  6. I used to do the same also...Never had a problem
  7. misfit

    misfit MOD SQUAD

    i never do,and never had any problems.i also never winterize,cause i never know when i might get a nice january day to get the boat out :D :D

  8. Well you guys got me wondering so I called Mercury.They said that if you only do this once a year it should not hurt it,but they recommend using fuel stabilizer and running it for 5 min.Then drain what fuel you can out of the lines.
  9. Whaler

    Whaler Whaler

    I have a 1977 6 Horse Johnson and I have been removing the hose and running all the gas out each time I leave the lake ever since I bought it because I don't know if I'll be back out in that boat or the other one. It hasn't hurt a thing. I don't winterize this motor either as I might take it out during the Winter if there is open water. I do winterize the 70 Horse though.
  10. Lewzer

    Lewzer Powderfinger

    I don't worry about the gas in the lines, just the gas in the carb.

    I don't understand why a 2 stroke would have issues with no oil or running lean because the oil is already mixed in the gas.
    I don't need stabilizer in the summer. In the winter the gas/oil is safely disposed of and I start with fresh gas/oil in the spring/late winter when I pulll the boat out for the first time.

    Used to do the same. Why don't you anymore?

    I plan on keeping the boat and motor for another 20-30 years. I just don't want to be doing something that will eventually catch up with me.
    Thanks for your help. It doesn't seem as though I'm hurting the engine by doing this.
  11. misfit

    misfit MOD SQUAD

    my boat and motor are already 26 years old and both still going strong :D
    i now put seafoam through it at least a couple times a year.cleans and stabilizes all in one dose.
  12. Lewis


    Gasoline will not go bad at all if you are only going to let it sit for 2 to 4 weeks.
    Someone else mentioned a good point about running a 2 stroke motor out of fuel.
    As they are running out of fuel they are also running out of much needed lubrication.
    A guy who has worked on small engines for many years told me this.
    He told me to even avoid it on my chain saw,weedeater,or any 2 cycle equipment if at all possible.

    Another point to consider is trailering on an empty float bowl.
    A bowl full of gasoline acts as a cushion for the bowl float and needle and seat valve.
    I would imagine this would get beat around pretty good if trailering with an empty bowl.
    My cure for this??
    On what you figure to be your last tank of the season,just add a can of Sea Foam that is available at NAPA.
    Not only will it decarbon your motor,it also has a fuel stabilizer added....problem solved.
  13. Lewis and Truck made a good point, if you run a pre-mix motor out of fuel, your also running it out of oil. The exception to that is on some oil injection motors. The ones that inject the oil before the carbs, it would be the same. But, some motors inject the oil directly into the cylinders, so they would continue to get lubrication. I doubt a couple times a year will really hurt anything, but adding a stabilizer is probably the safest way to go.
  14. Hetfieldinn

    Hetfieldinn Staff Member

    I was told by a very reputable marine mechanic that it is the fuel vapors, not the fuel itself that turns to varnish. Therefore, he told me to always leave gas in the float bowl, ie: don't disconnect the fuel line and run the motor dry.

    I always keep a fuel stabilizer, such as Sea Foam, or Stabil, in all of my gas motors (boats, chainsaws, mowers, weedeaters, ect), as well as my shed gas cans, because I never know when they'll get used the next time.
  15. He's right, I supppose. BUT, the bowl isn't the problem area. Fuel left in the jets is what causes problems, and there's no way to keep them wet.
  16. Lewzer

    Lewzer Powderfinger

    Good info all. Thanks.
    Looks as though I will stop doing this except when I pull the boat out before ice over. I will try out some Seafoam next time I fill up.
  17. I use Johnson engine tune over the winter like a few of the guys said. Cleans engine,stabilize gas,mixes with water. Have used it for yrs.,good stuff.
  18. mrfishohio

    mrfishohio Recovering Fishaholic

    I'm getting one of those new hybrid boats... ;)
    Electric motor and a small gas motor just like the cars. Just thinking out loud. Someone will make one. Put the batteries in the gunwales...maybe add a solar charger too. :D