Fog a 4-stroke?

Discussion in 'Bubba's Outboards' started by Star1pup, Oct 9, 2006.

  1. Star1pup

    Star1pup New Member

    I was told not to fog my 4-stroke, 9.9 Evinrude when I pulled the boat out for the winter. I was told to just run it empty and then put Sta-Bil in the tank. is this right? I had a gummed up carborator last spring and was told that fogging a 4-stroke could cause this problem.
  2. bigtimeblues

    bigtimeblues New Member

    missouri, macon
    Hey Bill. I used to use sta-bil in my snowmobiles when I lived in WY. They could sit all summer and would fire right up come winter. I don't let my boat motors set long enough to worry about it. But I am a believer in it. Just follow the directions and make sure you have it in your carb and fuel lines not just the tank.

  3. zappaf19

    zappaf19 New Member

    I take my plugs out and spray the fog in the cyl.s to keep the rings free. I use stabe in my gas.
  4. riddleofsteel

    riddleofsteel New Member

    If I know I am going to be down for a month or more I use Stabil in the last tank or so of gas. Then i turn the gas off when I am done and let the engine run out. My engine has a plug in the float bowl so I can drain the bowl and fuel lines for really prolonged down time.
    I might submit that if you have to put a whole lot of effort into engine "winterizing" you may want to fish more of take up duck hunting. Gives your boat year round usage.
  5. Bubbakat

    Bubbakat New Member

    For many years there was a widespread belief that simply shutting off the fuel at the tank and then running the powerhead/engine until it stops constituted prepping the motor for storage. Right? Well, WRONG!

    First, it is not possible to remove all fuel in the carburetor(s) or fuel injection system by operating the motor until it stops. Considerable fuel will remain trapped in the carburetor float chamber (or vapor separator tank of fuel injected motors) and other passages, especially in the lines leading to carburetors or injectors. The only guaranteed method of removing all fuel from a carbureted motor is to physically drain the carburetor(s) at the float bowl(s). And, though you should drain the fuel from the vapor separator tank on most fuel injected motors (when possible), you still will not be able to remove all of it from the sealed high-pressure lines.

    Depending upon the length of storage, you can use fuel stabilizer as opposed to draining the fuel system; but if the motor is going to be stored for more than a couple of months at a time, draining the system is really the better option.
  6. trnsmsn

    trnsmsn New Member

    Missouri Originally Now I
    I use Sta-Bil in my generator & four wheeler Due to periods of inactivity & I have let them sit for over 6 mos. w/o starting them & had no problems.

    I use Lucas fuel treatment in every tank on my boat & truck. It keeps the injectors clean in the boat & truck also(diesel).The manufacture claims it stabilizes fuel also.

    Just recently, several of my friends were having the discussion about fuel spoilage. Several of us agree that the fuel tends to spoil faster now, rather than when it was leaded(boy am I old !).

    Maybe the lead acted as a stabilizer itself ?
  7. Star1pup

    Star1pup New Member

    I was told that it is a good idea to run Sta-Bil all summer with a 4-stroke and I've been doing that this year. That should mean that any fuel left in the carberator should already have Sta-Bil in it. Last spring was the only time i had a problem with a gummed up carberator. I never could spell that word. I think I'll just do my best to drain it and hope I don't have to pay to have it cleaned again next spring. Our lake will have a thick cover of ice so the boat will be in my driveway all winter.
  8. JAYNC

    JAYNC Active Member

    Newport N.C.
    I never really winterize my boat since I use it all year long, if I'm not going to use it for a week or more I just start it and let it run for a while once a week. It seldomly freezes here so thats how I do it. I believe in my manual it does say to fog the cylinders and mine is a 75hp merc 4 stroke. I will have to double check though.
  9. JAYNC

    JAYNC Active Member

    Newport N.C.
    This is right out of my online manual, hope this answers everyones questions.

    Where to Store Your Boat and Motor

    Ok, a well lit, locked, heated garage and work area is the best place to store you precious boat and motor, right? Well, we're probably not the only ones who wish we had access to a place like that, but if you're like most of us, we place our boat and motor wherever we can.

    Of course, no matter what storage limitations are placed by where you live or how much space you have available, there are ways to maximize the storage site.

    If possible, select an area that is dry. Covered is great, even if it is under a carport or sturdy portable structure designed for off-season storage. Many people utilize canvas and metal frame structures for such purposes. If you've got room in a garage or shed, that's even better. If you've got a heated garage, God bless you, when can we come over? If you do have a garage or shed that's not heated, an insulated area will help minimize the more extreme temperature variations and an attached garage is usually better than a detached for this reason. Just take extra care to make sure you've properly inspected the fuel system before leaving your boat in an attached garage for any amount of time.

    If a storage area contains large windows, mask them to keep sunlight off the boat and motor otherwise, use a high-quality, canvas cover over the boat, motor and if possible, the trailer too. A breathable cover is best to avoid the possible build-up of mold or mildew, but a heavy duty, non-breathable cover will work too. If using a non-breathable cover, place wooden blocks or length's of 2 x 4 under various reinforced spots in the cover to hold it up off the boat's surface. This should provide enough room for air to circulate under the cover, allowing for moisture to evaporate and escape.

    Whenever possible, avoid storing your boat in industrial buildings or parks areas where corrosive emissions may be present. The same goes for storing your boat too close to large bodies of saltwater. Hey, on the other hand, if you live in the Florida Keys, we're jealous again, just enjoy it and service the boat often to prevent corrosion from causing damage.

    Finally, when picking a place to store your motor, consider the risk or damage from fire, vandalism or even theft. Check with your insurance agent regarding coverage while the boat and motor is stored.

    Storage Checklist (Preparing the Boat and Motor)

    Be sure to fog the motor through the spark plug ports. . .

    . . .and drain the carb float bowls before storage

    Multiple carburetors will mean multiple float bowls to drain

    HPDI and some EFI motors have a drain plug on the vapor separator tank, just like carburetor float bowls, they should be drained

    The amount of time spent and number of steps followed in the storage procedure will vary with factors such as the length of planed storage time, the conditions under which boat and motor are to be stored and your personal decisions regarding storage.

    But, even considering the variables, plans can change, so be careful if you decide to perform only the minimal amount of preparation. A boat and motor that has been thoroughly prepared for storage can remain so with minimum adverse affects for as short or long a time as is reasonably necessary. The same cannot be said for a boat or motor on which important winterization steps were skipped.

    If possible it is best to store your motor vertically on the boat or on a suitable engine stand. If you can avoid it, do not lay a 4-stroke motor down for any length of time, as engine oil will seep past the rings causing extreme smoking upon startup. At best, burning that oil will promote spark plug and combustion chamber fouling, at worst it could cause a partial hydro-lock condition that could even mechanically damage the powerhead.

    Although Yamaha and Mercury recommend storing all of their 4-stroke outboards in an upright position, both manufacturers say that you CAN store their smaller motors lying on their sides, but only one side and only under certain circumstances. Yamaha shows that all of their portable motors may be stored with the tiller handle side facing downward and, larger motors (even the non-portables) up to 60 hp CAN be stored with the Port side downward. Mercury only shows their portable units stored on their sides, and like the Yamahas, recommends that if this is done that the Tiller handle side (the Port side) be faced downward.

    On all 4-strokes, IF the motor is to be stored on the side, make sure it is first left in a vertical position long enough to ensure all water has been completely drained otherwise water could enter the motor through the exhaust ports possibly causing a corrosion problem. Obviously water left in the exhaust system of a motor which will be exposed to freezing conditions would be an even GREATER concern.

    NO motor should be placed on its side until after ALL water has drained, otherwise water may enter a cylinder through an exhaust port causing corrosion (or worse, may become trapped in a passage and freeze causing cracks in the powerhead or gearcase!). Check your owner's manual for more details if you need to store a motor on its side. However if you do store it this way, be sure to return the motor vertically a few days before intended service and check the combustion chambers for oil before cranking the motor.

    A word on engine fogging. We do it, we think you should too, but these days recommendations vary on how to perform it. Yamaha seems ok with spraying fogging oil either into the carbs/throttle bodies of running motors. Mercury seems that way too, at least on carbureted motors. On EFI motors they give a bizarre warning that the use of their Quicksilver Storage Seal may cause a buildup inside injectors. The only problem is, there SHOULD be no way for the Storage Seal to get INTO the injectors, unless you put it in the fuel system and don't spray it down the bore of the throttle body. In Mercury service manuals they simply recommend manually adding a small amount of engine oil to each cylinder, through the spark plug opening. If that's the way you want to go FINE, but we'd probably elect to at least use a fogging oil spray which will be more evenly distributed throughout the cylinder.

    1. Thoroughly wash the boat motor and hull. Be sure to remove all traces of dirt, debris or marine life. Check the water stream fitting, water inlet(s) and, on jet models, the impeller grate for debris. If equipped, inspect the speedometer opening at the leading edge of the gearcase or any other gearcase drains for debris (clean debris with low-pressure compressed air or a piece of thin wire).
    As the season winds down and you are approaching your last outing, start treating the fuel system then to make sure it thoroughly mixes with all the fuel in the tank. By the last outing of the season you should already have a protected fuel system.

    2. Change the engine crankcase oil and, if applicable, service the oil filter. Refill the crankcase and gearcase with fresh oil (for details, refer to the Oil and Filter Change procedures in this section). The motor should be run after the oil is changed to distribute the fresh/clean oil throughout the powerhead. Of course, the motor should be run for flushing and fogging anyway.
    Besides treating the fuel system to prevent evaporation or clogging from deposits left behind, coating all bearing surfaces in the motor with FRESH, clean oil is the most important step you can take to protect the engine from damage during storage. NEVER leave the engine filled with used oil that likely contains moisture, acids and other damaging byproducts of combustion that will damage engine bearings over time.

    3. Stabilize the engine's fuel supply using a high quality fuel stabilizer (of course the manufacturers recommend using Yamaha Fuel Conditioner and Stabilizer or Quicksilver Gasoline Stabilizer respectively) and take this opportunity to thoroughly flush the engine cooling system at the same time as follows:
    a. Add an appropriate amount of fuel stabilizer to the fuel tank (for most stabilizers it is normally about one ounce for each gallon of untreated fuel) and top off to minimize the formation of moisture through condensation in the fuel tank.

    b. Attach a flushing attachment as a cooling water/flushing source. For details, please refer to the information on Flushing the Cooling System, in this section.

    c. Start and run the engine at fast idle approximately 10-15 minutes. This will ensure the entire fuel supply system contains the appropriate storage mixtures.

    d. Just prior to stopping the motor fog the engine using Yamaha Stor-Rite Engine Fogging Oil, Mercury's Quicksilver Storage Seal, or an equivalent fogging spray. Spray the oil alternately into each of the carburetor or throttle body (EFI) throats (you'll likely have to remove an air intake silencer/flame arrestor for access). When properly fogged the motor will smoke excessively, will stumble and will almost stall.

    e. Stop the engine and remove the flushing source, keeping the outboard perfectly vertical. Allow the cooling system to drain completely, especially if the outboard might be exposed to freezing temperatures during storage.
    NEVER keep the outboard tilted when storing in below-freezing temperatures as water could remain trapped in the cooling system. Any water left in cooling passages might freeze and could cause severe engine damage by cracking the powerhead or gearcase.

    4. Drain and refill the engine gearcase while the oil is still warm (for details, refer to the Gearcase Oil procedures in this section). Take the opportunity to inspect for problems now, as storage time should allow you the opportunity to replace damaged or defective seals. More importantly, remove the old, contaminated gear oil now and place the motor into storage with fresh oil to help prevent internal corrosion.

    5. Finish fogging the motor manually through the spark plug ports as follows:

    f. Tag and disconnect the spark plug leads, then remove the spark plugs as described under Spark Plugs.

    g. Spray a generous amount of fogging oil into the spark plug ports. Yamaha recommends a 5-10 second long spray of their Yamaha Stor-Rite Engine Fogging Oil for each cylinder.
    On most Yamaha/Mercury motors you can disable the ignition system by leaving the safety lanyard disconnected but still use the starter motor to turn the motor. This is handy for things like compression tests or distributing fogging oil. To be certain use a spark plug gap tester on one lead and crank the motor using the keyswitch. If no spark is present, you're good to go.

    h. Turn the flywheel slowly by hand (clockwise, in the normal direction of rotation) to distribute the fogging oil evenly across the cylinder walls. On electric start models, the starter can be used to crank the motor over in a few short bursts, but make sure the spark plugs leads remain disconnected and grounded to the powerhead (away from the spark plug ports) to prevent accidental combustion. Also, if the fuel system is not already drained and/or the EFI system is not disabled, you run the risk of fuel spray washing away the very same oil you're trying to leave on the inside of the motor. If necessary, re-spray into each cylinder when that cylinder's piston reaches the bottom of its travel. Reinstall and tighten the spark plugs, but leave the leads disconnected (and GROUNDED) to prevent further attempts at starting until the motor is ready for re-commissioning.
    On motors equipped with a rope start handle, the rope can be used to turn the motor slowly and carefully using the rope starter. For other models, turn the flywheel by hand or using a suitable tool, but be sure to ALWAYS turn the engine in the normal direction of rotation (normally clockwise on these motors). Also, keep in mind that the flywheel on most Yamaha/Mercury outboards (even electric start models) is notched to accept an emergency starter rope. You can always use a knotted rope inserted into the notch and wound around the flywheel to help turn it.

    6. On carbureted motors, if the motor is to be stored for any length of time more than one off-season you really MUST drain the carburetor float bowls. Honestly, it is a pretty easy task and we'd recommend doing that for all motors, even if they are only going to be stored for a few months. To drain the float bowls locate the drain screw on the bottom of each bowl, place a small container under the bowl and remove the screw. Repeat for the remaining float bowls on multiple carburetor motors.

    7. For models equipped with portable fuel tanks, disconnect and relocate them to a safe, well-ventilated, storage area, away from the motor. Drain any fuel lines that remain attached to the tank. It's a tough call whether or not to drain a portable tank. Plastic tanks, drain em' and burn the fuel in something else. Metal tanks, well, draining them will expose them to moisture and possible corrosion, while topping them off will help prevent this, so it probably makes more sense to top them off with treated fuel.

    8. For boats with permanently installed fuel tanks, there's a huge debate going whether or not it is better to drain your fuel tanks completely during storage or to top them off. The first option allows you fill the tank with fresh fuel when the boat is removed from storage. But depending on temperature swings during storage you could amass a significant amount of water in the tank from condensation. You'd need to drain this water before re-commissioning. The later option is the easiest, especially for shorter term storage (one winter) and it prevents the formation of condensation, as there just isn't room for much air/moisture in the top of the filled tank.

    9. Remove the battery or batteries from the boat and store in a cool dry place. If possible, place the battery on a smart charger or Battery Tender, otherwise, trickle charge the battery once a month to maintain proper charge.
    Remember that the electrolyte in a discharged battery has a much lower freezing point and is more likely to freeze (cracking/destroying the battery case) when stored for long periods in areas exposed to freezing temperatures. Although keeping the battery charged offers one level or protection against freezing; the other is to store the battery in a heated or protected storage area.

    10. For models equipped with a boat mounted fuel filter or filter/water canister, clean or replace the boat mounted fuel filter at this time. If the fuel system was treated, the engine mounted fuel filters should be left intact, so the sealed system remains filled with treated fuel during the storage period.

    11. Perform a complete lubrication service following the procedures in this section.

    12. Except for Jet Drive models, remove the propeller and check thoroughly for damage. Clean the propeller shaft and apply a protective coating of grease.

    13. On Jet models, thoroughly inspect the impeller and check the impeller clearance. Refer to the procedures in this section.

    14. Check the motor for loose, broken or missing fasteners. Tighten fasteners and, again, use the storage time to make any necessary repairs.

    15. Inspect and repair all electrical wiring and connections at this time. Make sure nothing was damaged during the season's use. Repair any loose connectors or any wires with broken, cracked or otherwise damaged insulation.

    16. Clean all components under the engine cover and apply a corrosion preventative spray.

    17. Too many people forget the boat and trailer, don't be one of them.

    i. Coat the boat and outside painted surfaces of the motor with a fresh coating of wax, then cover it with a breathable cover

    j. If possible place the trailer on stands or blocks so the wheels are supported off the ground.

    k. Check the air pressure in the trailer tires. If it hasn't been done in a while, remove the wheels to clean and repack the wheel bearings.

    18. Sleep well, since you know that your baby will be ready for you come next season.
  10. jim

    jim New Member

    Jacksonville NC
    We have said it and discussed it many times on here.Todays gasolines go bad in a matter of weeks.For those of you that only use a fuel stabilizer when you think you wont be using the engine,you are asking for trouble.USE IT ALL THE TIME!!!! Its cheap insurance.If the gas has stabilizer in it it probably isn't necessary to run the engine dry.The gums and varnish come from the GAS deteriorating while it sits in the carb for long periods of time.Stabilizer prevents this.Fogging thru the spark plug holes won't gum up you carb,but it will prevent corrosion and rust on your cyl walls.Would you put your favorite rifle away after washing it down with gasoline and nothing else?:big_smile: :smile2:
  11. Star1pup

    Star1pup New Member

    Good advice, but did you ever try to reach the bottom sparkplug in a 2001 Evinrude 9.9 4-stroke? The engineer who designed it should be keel hauled! There seems to be no wrench that will get in there and taking the lower shroud off looks like a really nasty job.