Conference vicki::boats

    This octane has run my truck v6 for 77000 miles and this engine is in
    a1 shape I think if their is a problem its with the choice of oil they
    are using to mix with the fuel.I also have run my omc i/o for 100 hrs
    on 89 and had no troubles at all.That is what makes me think it maybe
    the oil thats at fault.

    About three weeks ago I was also around a Mercury/OMC dealer and
    service shop in Vermont. My father has done business with them for a
    long time and they are brokering the sale of his old boat.
    
    I happened to see a service bulletin from OMC regarding gasoline grades
    in both outboards and 4-strokes. It strenuously recommended premium
    gasoline not only for it's obvious higher octane rating (and thus
    resistance to knock) but also for it's blending which seemed to greatly
    reduce the build-up of carbon on the heads, valves, pistons, and piston
    rings. It said this was getting to be a significant problem with
    regular unleaded. One of the main problems was build-up on the piston
    rings causing the rings to stick and eventually break. This scores the
    cylinder walls with resultant loss of compression and worse. It
    recommended the regular use of an OMC product called "Carbon Guard" as
    a gas additive, as well as an aerosol sprayed into the carburetor
    called, I believe, "Power Tune" on an older engine. I know that
    Mercruiser makes comparable products. The owner said he recommends
    using premium gas and the gas additive, and that he is seeing more and
    more carbon-related problems, especially broken piston rings. He also
    recommends it for it's octane and showed us three different sets of
    broken and cracked pistons. He said that, unlike a car, you usually
    cannot hear knock in a boat engine from using too low an octane gas.
    Again, this is for both two- and four-stroke engines. My father's old
    outboard (1973 65 hp, 3 cylinder) had a broken piston ring/scored
    cylinder but the shop owner said this was not uncommon in those engines. 
    
    Anyway, it convinced me to go this way (premium/additive) on the new boat.
    (260 Mercruiser). The additive is 1 Fl. Oz. to eight gallons.
    
    Larry
    
    Larry

    
    I just replaced manifolds, they were loaded with carbon.
    
    But did not fail for this reason.
    
    Larry, whats the name of this product, and what does a qt. cost?
    
    JIm.

    Perhaps this should be another topic,but in line with the additives,
    has anyone tried  chemicals like octane boosters? I have a '71 Johnson
    60hp motor with LOTS of usage on it.It runs great,but I wonder about
    the octane boost.You can buy the stuff for autos in any dept. store and
    they advertise something like a 101 or more octane when added to a tank
    of gas.I wonder about mixing some other ratio with my tanks to get
    something in the higher 90's.The stuff will mix with gas,but how does
    it mix with the two stroke oil? I suspect it will but would hate to
    have it separate and end up with mega fuel after mixing up a few tanks
    and then running the dregs of the tank through the engine. Can you say
    holed pistons?
    
    Anyone try it with good or bad results?
    
    Thanks,
    Keith
    

    Jim - I believe the OMC products are "Carbon Guard" which is the fuel
    additive, and "Power Tune" which is the carb. spray. I do not
    remember the Mercruiser product names but I will look in a Mercury
    brochure I have at home tonight. The fuel additive I bought was
    probably about a pint and cost about $8 at Baert Marine and was what
    the service manager recommended. It takes 1 fluid ounce (2 tablespoons
    I think) to treat 8 gallons of gas. I think this stuff is probably sold
    under other brands at the discount places, as well. I thought the whole
    bottle would have to go in with each tankful and that was looking to be
    pretty expensive, but as usual as a last resort I read the label! I
    have to visit E&B/Bliss tomorrow so I will check for other brands
    there.
    
    Larry

    You might want to check with the PP vendors and see if real TEL,
    (tetra ethyl lead) can be used. A company in mesquite TX called
    Octane Boost sells a product called REALEAD which is the only
    real TEL additive I've seen. I have an old 4 stroke aircooled
    motor that will not run on anything less than 100+ leaded fuel,
    it runs like a top with this stuff. I add it to my 2 stroke motors
    as well and while I do cake the plugs I don't get carbon or
    detonation problems. Since it comes disolved in gasoline it will
    certainly mix with oil. I'am not saying try it, I suggesting that
    you check and see if the PP vendor approves.

    
    I recently purchased a 1983 90hp Johnson from a dealer in Rhode
    Island.  He suggested using the carbon gaurd and also produced a copy
    of the Maint. Bulletin, saying that they had seen an increase in carbon
    related problems over the past 2-3 yrs.  I've been using it in just
    about each tank...
    
    Interesting aside...In 1989 I bought a brand new Harley Davidson, and
    got the same exact presentation from the Harley dealer (Heritage, in
    Concord, N.H.) complete with graphic examples of parts they had
    replaced in engines they had worked on.  The interesting thing is that
    the Harley additive comes in the same shaped bottle, and is half the
    price of the Johnson product.  Neither label indicates the ingredients,
    so it's hard to say if it's the same stuff under a "marine" label. 
    Looks the same, smells the same, but for the $3.50 savings per bottle,
    it's probably not worth the risk...

    
    A strange co-incidence, i recently replaced manifolds on my
    boat. The drain plugs, which are at least 1" dia. holes
    were loaded with carbon. This week-end i had to clean the
    flame arresters,they were loaded with black soot.
    
    I'd say the black soot was carbon. With all the hype about
    cleaner gasoline, and the miraculous additives they claim
    to use, are we gettin poked.
    
    Gas is pricey enough, now we have to put in a decarbonizer
    in addition.
    
    Nothing like a double screwin.
    
    JIm

    Jim, it seems strange that you'ld have "carbon" in the form of black
    soot in your flame arrestor on top of your carb.  If the engine was 
    running properly, everything (ie: air, gas) should be going thru the 
    flame arrestor and into the carb/engine not the other way around.
    You're not back-firing thru the carb are you from having the timing out
    of whack or anything?  I would be concerned.  I would also thing that
    carbon is a "hard" deposit which becomes caked on a surface (like
    inside a combustion chamber).  Is it in fact a "black soot" material?
    Wayne

    Thanks Wayne,
    
    however most inboards have the problem, at least from what i can
    tell.
    
    On the salt, if your board by the CG, they will (if they're in a bad
    mood) write you up for it.
    
    The engines are running fine, i've had my share of maintenance
    this season.
    
    thanks, JIm.

    
      True enough. I really don't know exactly how the carbon forms
    around the intake, but I have seen it many times myself. 
    
    Wayne - Carbon will be hard if it has been heated a lot (like in
    a combustion chamber) but can certainly be soft as well. (Charcoal is
    almost pure carbon) It just depends on how it was formed.
    
    				Kenny

    I was looking at a piston out of a guys Merc here today.  You couldn't
    even budge the piston rings where the carbom was built up.  he had to
    buy a new motor.  Is this a problem for four stroke motors, too?
    Wayne

    
      I haven't heard of it causing *serious* problems, but from some of
    the replies in here, it does seem to be be a growing problem that
    should be watched carefully.
    
       When the rings start to stick, you get massive blowby which
    overheats the piston terribly. If you don't get a seizure out of it,
    you will at least horribly score the cylinder walls and it is a
    self-feeding problem. The extra blowby causes more piston expansion and
    more ring sticking and so even more blowby. If the engine is working
    hard at the time (When the ring starts sticking), the whole process 
    can happen in a few minutes or even a few seconds.
    
      I have been personally not worrying about it, thinking I would be
    very careful what I fed my engine, but with the increasing number of
    stories about it, I think I should also be looking into adding a
    decarboning additive from time to time - just to be on the safe side.
    Like they say on TV 'You can pay a little now, or a lot later'.
    
    					Kenny

    Yes, it does happen to four-strokes. Ring seizure happened on at least
    one of the cylinders of my 86' Toyota Tercel last fall at around
    120K miles (just well broken in for a Toyota). I have driven Toyotas
    for lots of miles for lots of years and never had seen this problem
    before. Both my mechanic and a magazine article (Popular Mechanics
    maybe) warned against using 'regular" gas, saying it had become real
    terrible stuff the last few years. But I was cheap and kept on using
    it. Cost me  over $800 even  with a "inexpensive" "shade tree" mechanic.
    
    Bill
    

    Re: "Carbon" on flame arrestors
    
    Any chance this is belt "dust"? My inboard wears belts pretty hard. I
    have a line of black belt dust on my engine cover next to the
    alternator. I also have some in my flame arrestor, which I clean
    occasionally.
    
    Chuck

    
    ditto on belt dust. You may need to take the pullys off and refinish 
    them.
    
    I use valve tech in every tank.
    
    Bruce

    Should an outboard which is running normally have the head(s) removed
    periodically to check for carbon build up?  If I pull the heads of my
    25 HP Johnson (1976), I KNOW at least one head bolt will break.  
    I have had no problems with my ob this year other than bad gas in the
    spring.  Should I leave well enough alone, should I put addititives
    in the gas?  I run it on premium after reading all the notes on ping.
    
    Jeff

    ALL 2 strokers should be de-carboned periodically. An afternoon and
    a top end gasket set is always cheaper than a bore job and a couple
    of slugs. I would think that a cleaning every few hunderd hours of run
    time or so would be appropriate. If its clean the first time make
    it 300 hours until you see how long it takes for real deposits to
    accumulate. With regard to breakin bolts, use "never seize" and/or
    brass bolts. When ever I replace exhaust fasteners I always use
    brass, never another problem... Check the piston skirts through
    the transfer, intake and exhaust ports, scorching below the 
    botton compression ring indicates blow-by and the need to remove
    the pistons and decarbon the ring galleries. Easy job but be careful
    that you don't mix rings.. Pretty simple really, take care of your
    equipment and it'll take care of you.... 

    Folks -- I have the same dust problem on my starboard engine -- I
    isolated it to belt.  No matter how tight I get the alternator belt, it
    still jiggles -- New belt -- Same problem.
    
    Jim, I'd carry a spare set of belts!
    
    Cap'n Ahab

    
    Check with a local INDUSTRIAL supplier of belts. There is a 
    belting material which comes in a roll, I believe it's a
    poly material, is cream colored, and you cut it to the size
    you need and use a special bonding agent.
    
    Also there are different grades of belts including cogged ones
    which are specifically designed for smaller diameter pulleys.
    As a solid belt travels around a pulley, the inner part is forced
    to compress while the outside stretches just a miniscule amount.
    The cogs in a belt prevent the compression stage and add longevity
    to the belts provided they are properly tensioned.  
    
    When/if you go to an industrial belt supplier, be sure to take 
    along the belt that was specified by the engine mfg.  This will
    allow them to determine if it's a 3L,3V,4L,4V,A,AX, or whatever
    to properly fit your pulleys.  If you do not have the original
    spec, they will have a guage set available to measure the depth
    width and angle of the pulleys.  For instance, an AX belt will
    NOT operate properly in a 4L pulley. It will bottom out, not give
    the proper grip and will not last long.
    
    Run your fingers along the sides of the pulleys, if they are
    nice and shiney like they were chrome plated and are more "U"
    shaped than "V" or have little ridges that you can feel, those
    are the telltale signs of wrong belt for the application,
    improper tension or mis-alignment.
    
    True, the internal combustion engine industry has done a great
    job in engineering thier componants such as alternators, smog
    pumps, compressors and what-have-you so that even veteran 
    mechanics pay little attention to belt alignment.  All it
    takes is one pulley not being perfectly parallel with the others
    by being further out, in or slightly angled (most common problem)
    cause the belt to rub on one surface of the pulley where it enters
    and leaves rather than enterring and leaving evenly with no friction.
    
    Fred

    I need some recommendations on who to take my engine to for possible
    carb/fuel filter/fuel line problems. I live in Worcester, so it seems
    as thought my options are down to Roy's Marina, USA Marina, Gouche
    Bros, or a place (can't think of the name of it) in Grafton.
    
    Who do people with experience at the places listed above recommend? I
    would like to get my motor back in less than a week, and I also do not
    want to pay throught the nose for this type of work. the motor is only
    a 3 hp Johnson. Any feedback is greatly appreciated. Thanks,
    
    
    
    
    
                                JS

    
    
    	Why not try and fix this one yourself. $20 or so for a crab rebuild
    kit, a small screwdriver and a beer and in one night you can do the
    job yourself. The fuel system on a 3hp is very simple. Also replace the
    inline filter and blow out the hose and thats about all there is to it.
    
    
    Paul
    

    Paul, does the "crab" rebuild kit do the fix or do you have to train
    the crab??
    

    
    	All depends on how many tricks you want the crab to do!
    
    Woops.....
    

    Ah yes, Paul, the world's foremost expert on crabs.  Last year he had
    to shave his beard 'cause of the nasty critters.
    
    djc