Mercury K1? Or maybe not?

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    kirkp

    US Member - 1 Year
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    #194842

    Hope you live in a local where you have access to some good meets. You could be like me and live in western Iowa where the closest is a days drive away.

    Kirk

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    opposedtwin

    US Member - 1 Year
    Replies: 748
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    #194871

    Kirk, good observation about why Carl may have detuned the store brand motors. I am fortunate that I live in southern Wisconsin where there are many chapter meets nearby and I attend them pretty frequently.

    Louis, can you explain the narrowed exhaust part you mentioned early in this thread? I’m not sure I follow you there.

    Bob has been kind enough to set me up with some of the parts I will need to get it going. Thanks Bob!

    Scott

    • This reply was modified 7 months, 2 weeks ago by Avataropposedtwin.
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    kirkp

    US Member - 1 Year
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    Topics: 9
    #195089

    Out in the storage today looking at my Sea King. Serial number is as shown. Noticed that on Sea Kings it appears that it’s a model KI and not K1.

    serial3

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    green-thumbs

    US Member - 1 Year
    Replies: 412
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    #195092

    I am unable to find mention of narrow passages in this thread.
    Until KE4 the cylinder exhaust ports were 3/8″ openings either
    side of a 1/2″ opening. Most KE4 and all Mark 7 had
    cylinders with 3 exhaust openings of 1/2″
    The Wizard WF4 and WG4 had the old pattern cylinders with
    the uneven exhaust ports as well as the old style reed block
    and chankshaft. KE4 and Mark 7 were rated at 7 1/ hp while
    Wizards twins (and Mercury KD4) were rated at 6 hp.
    The difference in power between K1, WA2 and either the
    1940 and 1941 Sea King was zero. They all had the poppet
    valve fuel mixer. Up market models of Mercury and Wizard
    singles had more power due to having a more efficient carburetor
    The Kiekhaefr made Sea King single did not upgrade to a carburetor
    as it was made to an entry level price AND Montgomery Ward
    had OMC made models for up market customers.
    Kiekhaefer may not have made much money from entry level
    models, but, they added volume for economy of scale production,
    Kiekhaefer was happy to make a range of models for Western Auto
    and even to create a twin cylinder model at their request.
    Postwar Mr. Kiekhaefr was in a better position to favor Mercury
    over Wizard,
    My opinion, which you are free to share or dispute.
    Louis
    edit
    If you were Mr. K and you had some left over Thor lower units , would
    you scrap them or cobble them into something that could be sold to
    someone willing to buy odd but cheap outboards. I have seen a streamline lower unit with a Thor powerheade. Hard telling what
    combinations of parts are out there, so I will only say most if not
    all.
    Horse power is a curious subject when it comes to Kiekhaefer…
    Per MW ad 1940 Sea King 8820 2.8 hp rated @ 3500 rpm

    Per Mercury Master Specification Chart
    1940 Mercury K1 2,5 hp rated @3800 rpm poppet valve
    1940 Mercury K2 3 hp rated @4250 rpm carburetor
    1940 Mercury K3 3 hp rated @ 4250 rpm carburetor

    1941 models had revised piston, rings, cylinders and crankcase
    which may account for some improved power output.
    MS series carguretors used in 1940 models and KB1A
    while AJ series models were adopted for other 1941 models
    Certified horsepower ratings were adopted by the industry to
    put and end to imaginative claimed power. I am not aware
    of conditions under which rated horsepower was determined.
    The .7 hp spread in itself probably did not lead to significant
    performance differences. However, carburetor linked to ignition
    advance made for easier starting and operation which did
    matter a great deal.
    Louis

    1941 KB1 2.9 hp rated @ 4000 rpm poppet valve
    1941 KB1 A 3.1 hp rated @ 4000 rpm carburetor MS type
    1941 KB2 3.2 hp rated @ 4000 rpm carburetor
    1941 KB3 3.2hp rated @ 4000 rpm carburetor AJ3A possibly AJ8A

    edit #2
    It may be that K1 and 8820 in actuality had same output and the chart
    is in error…they have identical powerheads that should produce same power… transposing numbers seems plausible as
    to why the the power and rated rpm differ.

    • This reply was modified 7 months, 1 week ago by Avatargreen-thumbs.
    • This reply was modified 7 months, 1 week ago by Avatargreen-thumbs.
    • This reply was modified 7 months, 1 week ago by Avatargreen-thumbs.
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    kirkp

    US Member - 1 Year
    Replies: 143
    Topics: 9
    #195102

    Louis, maybe he was talking about “Most if not all 1940 Kiekhaefers have the streamlined aluminum tower
    exhaust housing.”

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    opposedtwin

    US Member - 1 Year
    Replies: 748
    Topics: 234
    #195110

    Kirk, you are correct. That’s what I was referring to. After re-reading it however I realize Louis was referencing the legs in the many pics you all posted. Also thanks for the additional pics.

    While I’m waiting for the flywheel and sheave to arrive, I removed the magneto from my k3 model and installed it on the sea king. Save for the spark advance lever, they appear to be the same. I will have to go through the carb still in order to make it run but I’m one step closer.

    I took a green pad to the top of the crank shaft today and there is some rust that didn’t disappear. But most of it did! Do I dare take sand paper or emory cloth to it? The crank case does turn easily and it looks very clean inside.

    Scott

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    kirkp

    US Member - 1 Year
    Replies: 143
    Topics: 9
    #195114

    Louis or others will chime in but I believe these early Mercs share components. Don’t know if you already have it but I’m attaching a parts list for the early models.

    I don’t think taking some emory cloth to clean up the crank will be a problem as long as you don’t go crazy.

    Out of curiosity have you checked the compression? You could probably double nut the crank threads and use a drill to turn it over.

    Kirk

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    opposedtwin

    US Member - 1 Year
    Replies: 748
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    #195117

    Louis or others will chime in but I believe these early Mercs share components. Don’t know if you already have it but I’m attaching a parts list for the early models.

    I don’t think taking some emory cloth to clean up the crank will be a problem as long as you don’t go crazy.

    Out of curiosity have you checked the compression? You could probably double nut the crank threads and use a drill to turn it over.

    Kirk

    I haven’t checked compression with a gauge as I rarely do on small pre-1950 motors. Turning it by hand it seemed to have pretty good bounce.

    I do have some of the old charts that list parts. Turns out K1/K3 share many parts! I can use the flywheel and mag from my k3 to keep moving forward.

    Scott

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    opposedtwin

    US Member - 1 Year
    Replies: 748
    Topics: 234
    #195118

    So the carb is simply a fuel/air mixing valve, correct? What needs to be done to “go through” it? It looks really clean inside. Not really sure how one works. What is the function of the hole-filled chamber on the bottom? I’m assuming that’s where air is sucked in mixed with the fuel being metered by the single needle out front?

    • This reply was modified 7 months, 1 week ago by Avataropposedtwin.
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    kirkp

    US Member - 1 Year
    Replies: 143
    Topics: 9
    #195143

    Scott, you are correct that it is a simple mixing valve. Yours with all the holes is a new one to me but maybe someone will know what’s going on. Here’s a pic of the valve on my Sea King. Turns out the manual I have is too big to attach. Here’s the first two pages so maybe you can see if it’s different than what you have. If you want me to send it to you, send me an email.
    Kirk

    100_2261

    manual-1

    manual-2

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    green-thumbs

    US Member - 1 Year
    Replies: 412
    Topics: 38
    #195152

    Share and share alike,,well yes and then again no. The single cylinder
    models rapidly evolved. Amazingly, almost all improved design parts can be back fitted to earlier design. All are the same, but, all are different one way to put it. Between the two years there are fundamental changes in design. Within the two years there are variations in details.
    In tearing down a 1941 KB3 Mercury, I damaged the crankcase, a friend had given me a 1941 Sea King less tank and magneto,,,an easy swap. A friend had a 1946 WD3 with a damaged tower. The Sea King tower was the same and worked just fine. It started, ran and pumped
    like a fire engine. BUT, Kiekhaefer postwar Mercury and Wizard models began to have frustrating difference for parts swoppers,
    Louis

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    jnjvan

    US Member - 2 Years
    Replies: 42
    Topics: 1
    #195156

    Actually, that “carb” is a bit more than a simple air/fuel mixing valve. It contains a spring loaded poppet valve that opens and closes with each stroke of the piston. You will note that your motor does not have any reed valves. The poppet performs this function. When the piston moves down in the cylinder, it pressurizes the crankcase, and forces the poppet closed. On the piston’s up stroke, the resulting vacuum in the crankcase lifts the poppet off its seat, allowing air (which mixes with fuel metered by the needle valve) into the crankcase and allowing fuel past the needle valve. You will see that the opening for the needle valve is in the beveled seat for the poppet so that a closed poppet also stops fuel flow. You will be able to hear the poppet clanking on the seat, while the motor is running. These contraptions work surprisingly well.My 1941 Sea King with poppet starts easily and runs smooth. However, you won’t win any races with that motor. You will probably find that you need to adjust the needle valve for best operation as you move from idle to high speed operation, and vice versa, as there is no separate idle circuit.

    Kirk’s picture of the bottom of the valve shows a pin and screen. These also perform a function. To start a cold engine, push up momentarily on the pin, which lifts the poppet and allows a bit of fuel to flow past the needle. This fuel will wet the screen, acting to enrich the fuel/air mix and thus prime for cold starting, since there is no choke on these motors, either.

    John Van

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    kirkp

    US Member - 1 Year
    Replies: 143
    Topics: 9
    #195295

    John, great description of the operation. Any thoughts on the setup that Scott has?
    Kirk

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    opposedtwin

    US Member - 1 Year
    Replies: 748
    Topics: 234
    #195717

    I substituted the magneto from my K3 and now (along with the flywheel and sheave Bob supplied) I have a good spark on the sea king.

    In the disassembly/assembly I lost track of where the little wave washer goes. Is it underneath or on top of the cam?

    I need to clean the tank and get fresh gas to the motor and hopefully it will run.

    Scott

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    kirkp

    US Member - 1 Year
    Replies: 143
    Topics: 9
    #195768

    Scott, sent you an email
    Kirk

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