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Stuck Cylinder Head Bolt 1969 Johnson 6HP.

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  • cprodave
    started a topic Stuck Cylinder Head Bolt 1969 Johnson 6HP.

    Stuck Cylinder Head Bolt 1969 Johnson 6HP.

    A couple weeks back on a short run from dock my Model 6R69M suddenly quit with signs of overheating (engine quit, was very hot to touch and there was slight smoking around powerhead. I rowed home and tested in water tank. Engine was not making any "mist" (this engine has no peephole but has "mist" setudnp instead) indicating inadequate water flow. I removed thermostat cover and found extensive salt etc corrosion. I cleaned the thermostat cavity thoroughly but couldn't remove the cylinder head (one bolt/screw stuck) to do a deeper cleaning of the water jacket areas. I replace the thermostat and thermostat gasket/o-ring plus the thermostat cover gasket. Engine starts fine but still overheats. There is no mist coming out. I pushed a stiff wire up the mist hole and still no mist (I have found this technique often clears debris/buildup in peepholes).

    So here is the question: should I risk breaking off the one stubborn Cylinder Head Screw p/n 308728 or should I separate the powerhead from Main Drive Shaft to attempt cleanout from underneath in those areas? I am unsure if powerhead has ever been separated on this engine (a mechanic replaced the water pump around 5 years ago. Unsure on this design if pump/impeller can be replaced without separating powerhead from Drive Shaft).

    If I do attempt to remove the stuck cylinder head screw (other 7 of 8 screws have all been loosened) what is the best technique? Should I use Impact Driver with 1/2drive 3/8 socket vs. 3/8 socket with Breaker Bar? I have been soaking the stubborn screw with Liquid Wrench, transmission fluid etc for at least 1 week, but this screw is so tight I doubt that even capillary action is getting fluid in where it can do any good.

    Thanks for any input.

  • cprodave
    replied
    I got the Lower Unit Dropped and started a new Thread about surprise p/n I found in the Water Pump. "Close this Thread" I suppose. Thanks.

    Leave a comment:


  • oldboat1
    replied
    Try turning the prop by hand while operating the shift lever. Or insert a bladed screwdriver horizontally to move the connector (i.e., the shift rod).

    But you can disconnect the shift rod by removing either the top or bottom screw. Even with the screw removed, the brass connector might remain clamped in place until broken free (gently).

    Leave a comment:


  • cprodave
    replied
    Ok I am working to change the impeller. I tried dropping the lower unit per Leeroy'd ramblings: "There are 4 bolts that hold the lower unit to the exhaust housing, remove these. The lower unit should drop down maybe 3/8", but probably not enough to access the shifting rod coupler bolts through the gap created. Shift the motor into reverse, as this allows the lower unit to drop down about 3/4", enough to access one of the (2) 1/4" fine threaded bolts that are threaded into a brass coupler block which connects the upper to the lower shifting rods as shown by the red arrow in the photo below. You do not have to remove the upper coupler bolt, usually just the lower one. Once this lower coupler bolt is removed, if the lower unit will not drop enough to come loose, (these motors are different than most) pull your spark plugs and pull the starter rope or rotate your flywheel, or the prop while pulling down on the lower unit. This will rotate and allow the shaft dowel pin to align with a slot in the upper mid-section seal, (rotating sometimes up to 1/3rd of a rotation) the drive shaft now can come free and the whole lower unit comes off like all the others do. "

    What I see this far is (at best) access to the upper (not lower) fine thread bolt in the brass shift link coupling block.

    Is there any harm/complication by loosening the upper (vs. lower--as Leeroy suggests) coupling block screw? Any tips in getting a wider blade flat head screwdriver into this very narrow gap? A 90 degree screwdriver won't fit...

    Leave a comment:


  • tomhath
    replied
    Originally posted by cprodave View Post
    ...If that doesn't work I will next examine 5 year old impeller along with possible plugged copper intake tube. Thanks for the inputs.
    I'd change a 5 year old impeller as normal maintenance. If you don't have a clogged water tube yet you might well have one soon.

    Leave a comment:


  • cprodave
    replied
    Crosbyman thanks for tip on $4 keyboard duster, I have seized up transom clamps on another outboard...

    Leave a comment:


  • cprodave
    replied
    Sorry for delay in responding, have had limited time to work on this one. I used the time delay to allow extra soak time with penetrant, then a 3/8 socket 1/2 inch drive hand impact wrench. Corrosion in cooling passages was not bad except small passage near thermostat was nearly or fully plugged. I scraped out best as I could and am awaiting new head gasket. If that doesn't work I will next examine 5 year old impeller along with possible plugged copper intake tube. Thanks for the inputs.

    Leave a comment:


  • Crosbyman
    replied
    try freeze then heat … keyboard airdusters at dollar store are $4 ...held upside down they will freeze the bolt then try a heat shock while adding loose nut type products

    I had great success on a stuck tire bolt using…..snowblower teflon spay the stuff clear and slick

    patience brings joy….

    Leave a comment:


  • TMW123
    replied
    Originally posted by Joe Reeves View Post
    A five year old water pump?... Sitting or in use, five years of either is enough reason to replace it.

    Nobody's mentioned it... unless I missed it somehow. Normally heat applied via a hand held propane torch on the aluminum surrounding the bolt is the method to help break it free.
    I would start with the 5 year old water pump. Whether it solves the problem or not. As for the stuck bolt.. those suck. I would suggest some sort of controlled impact; either an air/electric impact set to low rpm or a handheld impact screwdriver with a socket on it. If you do not want to try that, grind it off, remove the cover and bank on kroil and some vice grips to twist the bolt out.

    Leave a comment:


  • Joe Reeves
    replied
    Originally posted by racerone View Post
    Read post # 2 ???
    No... I started to and just got to the part where one drills the head off... and about that time a old girlfriend stopped around just for old time sake. Hadn't seen her in years! Beautiful as ever, a body you wouldn't believe. The reason I say a "old girlfriend"... I really felt that we shouldn't be a couple as I was strongly suspicious she was a retired call girl and a nymphomaniac to boot,,, and within our first week together, I developed this iron clad feeling that I wasn't going to survive the month and it would be best to go our separate ways.

    Anyhow, we talked for hours (That's what she calls it now)... and my mind became befuddled to a point where post #2 got lost in the mail... or something. I will make a strong attempt to be more observant in the future Racer... Honest!

    Leave a comment:


  • racerone
    replied
    Everybody works to different standards.

    Leave a comment:


  • oldboat1
    replied
    Originally posted by racerone View Post
    ----Remove bolt with vicegrip.
    Vicegrip is a good description of what Jeffrey Epstein and his buddies received from the minor girls he recruited. A visegrip should have been used on the s.o.b. (or Joe’s hand held torch….)


    Leave a comment:


  • racerone
    replied
    Read post # 2 ???

    Leave a comment:


  • Joe Reeves
    replied
    A five year old water pump?... Sitting or in use, five years of either is enough reason to replace it.

    Nobody's mentioned it... unless I missed it somehow. Normally heat applied via a hand held propane torch on the aluminum surrounding the bolt is the method to help break it free.

    Leave a comment:


  • 54bobby
    replied
    try 1 good whack with a heavy hammer. make sure you hit it flush and don't hit the cyl. head, just the bolt. sometimes a good inward strike will break them free.

    Leave a comment:

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