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  • Can't start Flathead - need help

    I could use some suggestions. I’ve always prided myself in being able to get anything started over the years but I am stuck.
    I have a 1947 WL 45. Sitting for over a year. Pretty good shape, original condition. I haven’t been able to get it started. Here’s what I’ve done:
    Cleaned out gas tank (not much in there) put in new gas.
    Cleaned gas filter, not much crud, a little.
    It has a new shut off valve. I took it apart, followed fuel to carb to make sure it has flow. It does.
    It has compression.
    It has spark at the plugs (took each out and checked for spark) and points. Gap in each is good.
    Checked valve/tappet clearance.
    Battery is charged & lights (including brake light) work.
    Float in carb was stuck. Not any crud in bowl but float did not swivel on float pin/fingers.
    Now float works and float valve opens and shuts gas off. I don't totally trust this float though.
    Low speed adjustment is 3 turns out . . . I’ve tried to start it with 4 & 5 turns out.
    High speed needle is 2 turns out.
    When I kick to prime (tried 3 kicks, 4, 5) with full choke I get gas at the carb (I wipe it down with a rag ‘cause I’ve had small flames at the carb, yikes,). I kick with dist advanced (turned full clockwise . . . tried no advance, half advance, etc) I get a pop, sometimes a good loud pa pop.
    That’s it. Never a double or triple pop like she’s gonna catch. It’s been a month now, dang. I have to be missing something!!
    I’m getting gas when I prime it. So much that I wipe with a rag to prevent a flame there. My next step is to take the rest of the carb apart and check passages. I kind of anticipated that suggestion. Any other suggestions? Any help would be appreciated . . . thanks.

  • #2
    You didn't mention spark timing, have you checked it? Also the small lobe on the points cam fires the front cylindar. Sometimes a motor with a lot of carbon build up that has been sitting for a long period will hold excess fuel in the carbon and not fire clean(that is my definition if it makes sense). If timing and all else is correct I would try drying the combustion chambers with compressed air.
    Kerry
    Kerry AMCA # 15911

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    • #3
      do the plugs look wet? maybe the gas is not getting into the cylinders.
      rob ronky #10507
      www.diamondhorsevalley.com

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      • #4
        I have discovered that mine only needs 1 prime kick. If I do more, and like you said gas spills out of carb, then I have flooded it and I either have to wait or hold the throttle all the way open before it will start.
        Bob Selph
        1933VC/1934LT Sidecar
        1940 Sport Scout
        AMCA#15215

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        • #5
          Have you tested your manifold for air leaks? Also have you tried a very small squirt of starting fluid to see if if fires up?
          ------------
          Steve
          AMCA #7300

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          • #6
            Good Stuff

            WoW, Great imput. I will try it all.
            Interesting point kg . . . have never heard of that before (carbon holding gas), gives me another tool to use. You said the small cam fires the front cylinder, not sure what your point was with that??
            BTW, No I haven't looked at spark timing. Have to delve into my manual for the "how toos" on that.
            I've tried starting fluid Ohio (big squirt, not small one...shhh, don't tell anyone on this post but got a small fire with that one), haven't tested for air leaks though.
            rwm I've got the carb off and am going to make sure the passages are not blocked . . . make sure gas is flowin' to the cylinders.
            bselph, I've wondered about that. In the past I've primered the hell out of bikes with no prob. I may be flooding the bejesus out of it. Out of all the combos I've tried I haven't tried 1 prime, go figure...
            Now just have to find the time to get to it, let you know, thanks all!

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            • #7
              Dear Hardly, you didn't say if you had the bike running a year ago. What kg is saying is that you need to make sure the front cylinder fires when the small end of the timer cam is just opening the points. With the Harley wasted spark system, it's possible to get the bike running on either cylinder with no hope at all of ever getting the other one going. This sends you off to carburetor and other adjustments which just make things worse. I recently finished a rebuild, fired up the bike, ran it up the road and thought it was pretty soggy, found only one exhaust pipe hot, then had to turn the circuit breaker a large amount to get both cylinders firing. It happens. A possible tip after the bike failing to start is to give it a few vigorous kicks with the throttle wide open. This can clear it if over-choked. Good luck.

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              • #8
                Did you pull the spray nozzle out of the carb body to chech bore and bleed holes?
                Toe

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                • #9
                  Both plugs spark but I never thought to check if I have a spark at the "small end"

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                  • #10
                    No . . . carb is on the bench - will do

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                    • #11
                      Update. Spent time this last weekend & went through carb. I was a bit disappointed, was hoping to find them gummed up. Passages seem to be clear. Pulled low & high speed needles, nothing looked bad. Wiped them down, a little carb cleaner in the passages and used the air compressor to blow through passages.

                      Plugged the bottom hole of the float bowl, filled with water to make sure float was “floating”. It was. Dried it out before reassembly.

                      Pulled both plugs . . . they were sparking at “big” & “small” part of dist cam. Again I was disappointed not to find something wrong . . . dang!
                      Primed once . . . shot of starting fluid . . . nothing.
                      Primed twice, 3 x’s. Got just a pop.
                      It sure seems like it want to fire but feel like I'm missing something . . . something simple

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                      • #12
                        Look at this link and scroll down to the bottom of page 40 and the top of page 41. If you do not have a Service Manual you Should Get One. By the way the Timer goes Counter Clock Wise to advance. This should explain what people have been trying to tell you to do.
                        http://www.hydra-glide.com/phpBB3/vi...p?f=109&t=7017
                        http://laughingindian.com/
                        http://flatheadownersgroup.com/
                        A.M.C.A. Member Since 1986

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                        • #13
                          If all else fails, check to see if you have a cam out of time. I had a freshly rebuilt flathead motor that would fire on one cylinder and then spit raw gas out carb due to person that put motor together had one cam one tooth out of alignment. Either pull cam chest cover or pull head off cylinder which is not firing and it will be apparent that valve is out of time. I had an intake valve that was partially open when the cylinder fired.

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                          • #14
                            Yes I have 2 service manuals and Palmers book. Thanks for the imput.

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                            • #15
                              Guess next step would be to pull cam/gear cover. See if they're lined up right. Just doesn't look like that cover's been off for 60 years or so.

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