Tune-up question??

Discussion in 'Bubba's Outboards' started by puddle jumper, Oct 22, 2008.

  1. puddle jumper

    puddle jumper Well-Known Member

    Messages:
    1,507
    State:
    NW.Georgia
    Willard you out there...

    Ive been running my O/B for a good 4 year's pretty hard and its time for a tune up, its getting harder to start but runs fine, just wondering if you guys do your own tune up and what do you do,,, new plugs,, lower unit oil,, water pump? carbon guard??
    This boat has to last me a long time and I want to take good care of it..
    oh, and its a 50 hp merc. 2 stroke, 04 I think..:roll_eyes:

    Thanks guys,
    Puddle :wink:
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Yep change the plugs out and be sure to gap them at factery recommendations and also use the type of plugs that are already in it. You know those work well. Change the lower unit oil and replace those little round gaskets that are under the fill and drain screws. If the water pump hasn't been done in 4 years its time to replace it also. As for carbon guard its a good product but I use seafoam because its easier for me to get and works good also.
     

  3. puddle jumper

    puddle jumper Well-Known Member

    Messages:
    1,507
    State:
    NW.Georgia
    Thanks a lot Willard,
    Didnt know if there was any other adjustments that need to be done,,
    Puddle:wink:
     
  4. pythonjohn

    pythonjohn New Member Supporting Member

    Messages:
    11,533
    State:
    F L A Swamps
    I also use the seafoam, works good for me.
     
  5. katsandsuds

    katsandsuds New Member

    Messages:
    157
    State:
    North Caro
    Puddle,
    The seafoam is great stuff, not cheap though. There are a couple of ways to use it, and I do a combination of both. For general maintaince (50 hours or so), I carry a small gas can an disconnect my main fuel line to the tank, drop it in the small gas can with about a gal of gas and a good amount of seafoam. Run the boat for a 20 mins or so then hook the main line back to the fuel tank and run the boat another 10-20 mins to blow it out.
    Ever couple of years I use a squirt bottle and with the motor running on the muffs at the house, spray straight seafoam into the carbs until the motor stalls. Then I remove the plugs and squirt more into the plug holes. Let it set several hours then crank it up and run it at fast idle of a few mins to clean it out. It will smoke up the neighborhood, so if the fire dept shows up, don't be suprized:roll_eyes:. (if you google decarbing marine engine, you should get lots of info on the seafoam and other products and how to use them)
    I would also change the fuel filter during the tune up process as well. I do agree with a water pump rebuild, new impeller at a minimum. Those things are a rubber type material, and wear out. I change mine every couple of years. I have heard too many horror stories, and if it goes south, they go quickly, and you will lose you flow to the powerhead, causing overheating very quickly. Good luck, hope this helps
     
  6. corklabus

    corklabus New Member

    Messages:
    359
    State:
    West Virginia
    I've run into an unexpected occurrance with this tune-up stuff. My old boat seemed to do okay and has ran smooth ever since I got it two years ago. I did all the lower unit and water pump stuff and everything stayed pretty much the same. No noticeable difference. Then I got to wondering if the Seafoam was a good preventative idea, so I mixed up a fresh tank with the sea foam in it and ran about half of the tank through it. Now I'm getting an occassional surge that's really strong.....almost like the motor is gaining access to an extra carb and cylinder.
    It's an old '73 115hp Evinrude and if the motor is "supposed" to run as good as it does when it hits that surge, the thing would litterally fly. Not that I wouldn't appreciate the added performance, but I'm wondering if the performance would be normal or am I experiencing something that may be leading toward damage ? I also used new plugs a couple months before the Seafoam
     
  7. puddle jumper

    puddle jumper Well-Known Member

    Messages:
    1,507
    State:
    NW.Georgia
    Hey Cecil,
    You might try doing a compression check to see what the numbers look like, that gives you a pritty good insight to how healthy the motor is..

    Puddle
     
  8. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    did you change the plugs or cleaned the old ones
     
  9. corklabus

    corklabus New Member

    Messages:
    359
    State:
    West Virginia
    I had used New plugs. Same thing that came out of it.........purchased at Wally-World of course......

    When first installed the boat ran like a scalded dog all day, then next time, went back to its' normal performance level. I never really questioned the performance much because it seemed normal. I just got to wondering what made it run so exceptionally good that one particular day and thought that just maybe it could use a little Seafoam type cleanout. Couldn't see what it could hurt. I'm wondering now that maybe one of those Wally-World spark plugs might just not be firing right......and if the Seafoam is cleaning all the crap out of the thing, new plugs again might be the answer. Another thing is that this particular spark plug doesn't have a visible cleanable electrode. It's just circular and flat at the tip.
    I considered testing compression when I first got the boat and then over looked it. I'll have to do that just to be sure. Next question is ....What percentage of difference is acceptable for an outboard of this age ?
    I'm thinking 20% maximum ??
     
  10. katsandsuds

    katsandsuds New Member

    Messages:
    157
    State:
    North Caro
    Cork,
    From what I have read, the compression on all cylinders should be within 10%. Ideally you want them all to be even.

    As for the surging issue, that sounds odd. It sounds like you are getting more fuel at certain times, or you are getting spark on a plug part of the time.
     
  11. katsandsuds

    katsandsuds New Member

    Messages:
    157
    State:
    North Caro
    I hit submit before I was finished, sorry. The compression test should tell you if you have a cylinder issue, stuck ring for example.

    If it is fuel related, you could have trash in your fuel system that is breaking loose from time to time, giving you extra flow in brief spurts. This could be anywhere from the tank and pickup to the fuel filter to the carb and jets. As for the ignition, you could have a loose plug wire, worn distrubutor or cap, etc that is making connetion from time to time. If a plug is misfiring, there should be evidence on the plugs when you remove them for the compression check. Not completely sure how the distrubtor works on outboards, but in a car engine, if the dis gear is worn, it can cause a "shiftyness" in the timing and be advancing and retarding at different times, which could lead to surges in the power as well.

    The seafoam should have only affected the fuel system or a stuck ring and not the ignition system. Inspecting the plugs carefully will be a good indication if the is a ignition problem that is not timing related.
     
  12. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Take those surface gap plugs out and go get some QL77JC4 champion plugs and gap them at 35 and see what a difference it will make in idle and performance.
     
  13. corklabus

    corklabus New Member

    Messages:
    359
    State:
    West Virginia
    In an ideal world a 10% difference for compression testing would be great, but this is an extremely old and more than likely highly neglected engine before I aquired it. My guess of 20% was making allowances without looking at an expensive rebuild.
    The difference in fuel amounts could be a good guess. I've heard somewhere on this site that the inside of those rubber hoses deteriorate and collapse. Thanks for reminding me of that. I haven't changed that supply system yet and I certainly meant to do that.