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Conference vicki::boats

Title:Powerboats
Notice:Introductions 2 /Classifieds 3 / '97 Ski Season 1267
Moderator:KWLITY::SUTER
Created:Thu May 12 1988
Last Modified:Wed Jun 04 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1275
Total number of notes:18109

747.0. "Johnson 35 & 40 hp outboard starting problems" by COGITO::ZIKA (z) Sun Sep 02 1990 10:44

         Some friends took out a 1962 mechanical shift Johnson 40 on a
        fiberglass hull 15-footer and a 1963 mech shift Johnson 35 on a
        15-ft aluminum hull. Neither one starts easily and the Johnson
        35 blows the doors off the Johnson 40. To start the 35 we used
        Ether and started it five times before we were able to place it
        in gear and keep it going. After that she ran fine the rest of
        the day. The Johnson 40 started fairly easily the first time
        and ran well until shut off. The warn engine started very
        poorly. I eventually removed the gas soaked plugs and cleaned
        them with a T-shirt and we managed to get her going.

        Not knowing much about boats motors.. My guess is 

        (1) Carbs needs rebuilding 

        (2) Points/condenser need replacing which requires some sort of
        gear puller for the flywheels

        Can someone desribe the procedure necessary to rebuild the Carb
        and/or replace the, points. For instance: What should the points
        be gapped at and is distributor grease necessary (how much)?

        When rebuilding the carb are there any special settings and or
        adjustments on the carb. For example, what should the rich/lean
        be set to (two and 1/4 turns is the current setting).

        Considering how long these boats were stored (five+ years) they
        run extremely well.

        How can we make a Johnson start like she just came from the
        showroom? -- Chris
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747.1ROBOAT::HEBERTCaptain BlighTue Sep 04 1990 10:4131
Assuming the engines are mechanically in good shape:

 -case seals intact
 -rings not frozen 
 -reed valves intact
 -new spark plugs with the right gap
 -you get a fat BLUE spark
 -you have fresh gas with the correct oil mixture
 -you are able to pump up the squeeze bulb until it gets quite firm
 
--- they should start. 

I would NEVER, NEVER use ether on an outboard motor, particularly one
that is in questionable condition. The air/gas/oil mixture is sucked in
thrugh the carburetor air intake, passed through the crankcase where it's
used to lubricate everything, then into the combustion chamber. It's not
uncommon for the cylinder explosion to creep back into the crankcase.
Ether is so volatile that the crankcase could explode. Plus, ether tends
to wash the oil off the needle bearings in the crankcase; instant
scoring.

You might run some OMC 2+4 (or is it 2+2?) fuel conditioner through them

But. If they were put away with gas still in the carbs, the guts of the
carbs might be gummed up with residue from evaporated gas. I think that
means a carb rebuild.

Those engines should start within three pulls when cold (first time that
day), and on one pull the rest of the day.

Art
747.2Start with a tune up ...SITBUL::FYFETue Sep 04 1990 10:5217
    I would suspect the electrics before I would start on the carb.
    Carbs are very simple and rarely fail. You may wish to drain the
    carb bowl to remove any sediments that may be present.

    Start on the tune up. Make sure you check the ohms reading for each
    of the coils be within spec. Replace the two sets of points/condenser
    and set to spec. Any boat shop can tell you what the proper gap is.

    Also check the plug wires very carefully. A worn or broken plug
    wire can be the cause of many performance problems from rough starts
    to won't run at all.

    The reasons for the performance differences span from the performance
    of the motor to improper propeller pitch to lower end depth.

    Start with the tune up.
747.3Still wondering about how to change pointsCOGITO::ZIKAzTue Sep 04 1990 13:4113
    .re last 2
    From what I understand (1) Never use Ether (2) Rebuild the Carb
    (3) change the points and condenser (4) Check the electrics
    
    Any tips on changing the Points? Is a gear puller really necessary?
    The gear puller I have is medium sized and meant for a three-six inch
    gear. Do you think it will work?
    
    I found a Johnson Dealer across from the Pheasant Lane Mall in Nashua
    and will try to get some info from them when thry're open.
    
    	Thanks for the info, Chris
    
747.4Get the service manual for the engine too!SITBUL::FYFETue Sep 04 1990 14:3813
    
    You will need a flywheel puller which uses three screws to attach the
    flywheel to the puller. Do not use a standard gear puller as you
    can damage the teeth of the flywheel and even warp it.
    
    Second, since the plugs are getting wet with fuel I would put off
    rebuilding the carb till after the electrics are dealt with
    and tested (tune-up-wires-plugs).
    
    You can get a puller at Sears in the mall or if you live near Milford
    I could come over and pull the flywheel for you.
    
    Doug.
747.5MAGNETO PLATE COULD BE WORN ALSOBIZNIS::CADMUSFri Sep 07 1990 16:4525
    
    
     BOth these, motors are a little long in the tooth. a common problem
    with these older magneto ignitions is that the magneto plate (the plate
    that the coils and points are mounted on) gets worn and sloppy where it
    rotates around the engine block- check the palte fro any sloppiness- I
    have seen them so bad that hou could open and close thepoints by
    wobbling the plate.
    
     If the carbs are adjusted properly, the engine should start up cold
    w/choke or hot w/o choke on one or two pulls. I and my son have had 4
    of theses basic 35/40 engines o=ver the years- they are tough
    ,relioable, simple.
     
     Get yourself a meanual- get the carbs adjusted, check
    points/plugs/wires/mag coils, and mag plate. Use fresh gaso;ine with
    the correct gas/oil ratio and she should start right up.
    
     The ignition sysrtem on all these old 2 cyl OMC enginwes is the same.
    Poinmts,condensor,coils are interchangeable. They are also the most
    unreliable part of the engine- magneto coils and condensors frequently
    fail- also the plugs used to dib=ve me nuts- one drop of water in the
    gas and they were history- same if a plug got oil fouled. Other than
    t5hat you couldn't kill these engines.
    
747.6Timing is everythingDECWET::SCHMUHLWed Sep 12 1990 15:3810
    The warm starting (hard) sounds more like too advanced timing. One or
    two degrees can make the difference between hard starting and fouling
    plugs. Start with checking the timing on the one who starts different
    when hot. Check also that the advance mechanism isn't binding. BTW,
    old Johnsons run best when you open the throttle widest, back off until
    just before the revs die down (takes a little practice and feel). This
    allows the engine to fully advance the spark without over driving the
    carbs (max RPM + min fuel = best performance)
    
    Larry (who owned lots o' Johnsons)