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  1. #1

    Join Date
    Oct 2015
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    7

    Default Shovel with mag hard to kick when warm...

    OK Theres a potential can of worms about to open here.

    I have a 1980 Shovelhead chop with a Morris M5 Mag (the one with auto retard), Super E carb and no battery on what I believe is a fairly recent rebuild from the PO (Really good compression).

    Thing runs so damn good, and I know the starting procedure from cold and can get it started in 1-3 kicks. Also if I stop for gas most of the time its a 1 kick, but sometimes its a lot more.

    My main issue is that if its not just a quick stop for gas, like a 20 min wait, where the bike is warm but not hot, the thing is a fucking pain to start. Like I mean 20+ kicks. that cant be right. I have a switch to turn the mag off so I can drain the fuel, and still wont start. Surely if its warm it should just be a little squirt of gas and away. Anything I can troubleshoot? I have checked pushrods (They seem fine). I have checked timing with the Morris tool and its right on. Should I be looking at my spark plug gap or even type of spark plug? Its all I can think is left.

    Cheers all for any input.

  2. #2

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    May 2015
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    Quote Originally Posted by tom4130 View Post
    OK Theres a potential can of worms about to open here.

    I have a 1980 Shovelhead chop with a Morris M5 Mag (the one with auto retard), Super E carb and no battery on what I believe is a fairly recent rebuild from the PO (Really good compression).

    Thing runs so damn good, and I know the starting procedure from cold and can get it started in 1-3 kicks. Also if I stop for gas most of the time its a 1 kick, but sometimes its a lot more.

    My main issue is that if its not just a quick stop for gas, like a 20 min wait, where the bike is warm but not hot, the thing is a fucking pain to start. Like I mean 20+ kicks. that cant be right. I have a switch to turn the mag off so I can drain the fuel, and still wont start. Surely if its warm it should just be a little squirt of gas and away. Anything I can troubleshoot? I have checked pushrods (They seem fine). I have checked timing with the Morris tool and its right on. Should I be looking at my spark plug gap or even type of spark plug? Its all I can think is left.

    Cheers all for any input.

    Its not the mag, plugs or timing. Its the carb or an intake lake that gets worse when things get hot and expands

  3. #3

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    May 2015
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    One other thing. You said you checked the PRs and they "seem" fine. PRs should be checked when the engine is STONE COLD. With cam (lifter) its lowest point, adjust PR so there is just a tad of drag.

  4. #4
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    Solid or hydro lifters?
    You can actually check solids when bike is hot. Make sure they still spin anyway.

    Do you have the phelonic spacer behind the carb?

    Yer fuel tank venting?

    Set the float level slightly low. Esp If you've got that gangster lean.

    Hands off that throttle while kicking! Or make sure you've a steady hand anyway.

    Is there such a thing as heat soak affecting the magnets in the mag? Idk just thinking out loud on that last one.

  5. #5

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    Oct 2015
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    Thanks docmel, yeah I did check when stone cold, however perhaps they are slightly too tight. It could be that once the bike is hot, they have expanded and are no longer as loose as they should be. I will double check thanks man.

  6. #6

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    Oct 2015
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    @Sky thanks man this is great stuff to check.

    Solid lifters that I checked when cold, but I will double check to make sure that they are not tighter than they should be.

    I dont have a spacer behind the carb I dont think, however the carb could probably do with a cleaning. I am running a Velocity stack too, could it be that its not getting the correct 'still atmosphere' because I havent got a regular breather?

    Tank venting is fine I have double checked that, and have clear lines so know that the carb has plenty of fuel. Good call on the float level, and yeah I never give it gas when kicking warm, however I get to the point when I try everything once I'm 20+ kicks in!

    Heat soak in mag meaning that when hot the mag may be losing spark as the magnets arent strong? I can check spark when warm but I'd like to think that wouldnt be the case.

    All awesome stuff guys I will run some tests. Cheers

  7. #7

    Default

    Quote Originally Posted by tom4130 View Post
    OK Theres a potential can of worms about to open here.

    I have a 1980 Shovelhead chop with a Morris M5 Mag (the one with auto retard), Super E carb and no battery on what I believe is a fairly recent rebuild from the PO (Really good compression).

    Thing runs so damn good, and I know the starting procedure from cold and can get it started in 1-3 kicks. Also if I stop for gas most of the time its a 1 kick, but sometimes its a lot more.

    My main issue is that if its not just a quick stop for gas, like a 20 min wait, where the bike is warm but not hot, the thing is a fucking pain to start. Like I mean 20+ kicks. that cant be right. I have a switch to turn the mag off so I can drain the fuel, and still wont start. Surely if its warm it should just be a little squirt of gas and away. Anything I can troubleshoot? I have checked pushrods (They seem fine). I have checked timing with the Morris tool and its right on. Should I be looking at my spark plug gap or even type of spark plug? Its all I can think is left.

    Cheers all for any input.


    my 1974 shovel rebuilt as a 80" had all those same symptoms, with a dyna s ignition.. it was so bitchy i put e start on it.whats weird is when it wouldnt start off the kiker it would start in about 1 revolution with the e start.

    cold or just shut off it would kik fine. let it sit and soak for 20 min and it would just chuff and act dead.

    after a few thousand mile it got much better. now if it does the chuff and act dead thing. i turn off the key, run it thru about 3 times and turn key back on and kick.usually starts fine.

    i think it just needed to be broke in and get to know me.

  8. #8

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    Oct 2015
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    Yeah man its so weird! I do the turn the key off and kick it through a few times to drain the gas and try again. Sometimes all good, sometimes not.

    I did hear about some ignitions requiring the motor to turn one full revolution to start and I wonder if my pushrods are a little tight and not allowing that when hot.

    Havent gotten to the bike yet since this post but will try a few things out.

  9. #9
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    When I was a teenager I fought with a combine that wouldn't start hot that had a Fairbanks mag for two summers. It ran like a top and always started first or second pull cold sometimes started right up hot other times it took a hour or two. The hotter it was out the worse it got. Replaced dam near everything, carb, fuel pump, wires plugs etc. and finally I put a coil and condenser in it out of desperation they both tested good but replacing them dam sure fixed it. Sometimes electronics fail during a hot soak but not any other time.
    Dusty

  10. #10

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    Oct 2015
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    Dusty thanks for the reply man.

    Yeah I wonder if that could be the problem. I will definitely try another look at my pushrods but it starts from cold too well to be that, unless the heat expansion is making the difference. Other than that I feel like heat soak to the mag may be a potential issue.

    Issue is that I am running the mag with no battery so not really easy to go back to a battery without a load of work.

    For anyone that curious, heres the motor in question:

  11. #11

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    correct me if im wrong, i dont know much about mags. but basically when you kik the motor over it kind of cocks the mag like a hammer on a revolver,then when the engine reaches a certain point, the mag fires the plugs.ok it should fire the same kiked fast or slow?is that correct.

    also with a mag the battery is not needed unless you want lights without the engine running?

    oh and in my experience if there is a condensor in the equation. it can still run but the condensor can be shit. they are weird little devices. try to get a blue streak condensor.

  12. #12
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    Quote Originally Posted by ridgerunner1965 View Post
    correct me if im wrong, i dont know much about mags. but basically when you kik the motor over it kind of cocks the mag like a hammer on a revolver,then when the engine reaches a certain point, the mag fires the plugs.ok it should fire the same kiked fast or slow?is that correct.

    also with a mag the battery is not needed unless you want lights without the engine running?

    oh and in my experience if there is a condensor in the equation. it can still run but the condensor can be shit. they are weird little devices. try to get a blue streak condensor.
    Some very few Harley Fairbanks have a impulse like you describe most just turn at half crank speed and at kick start cranking speed the voltage at the points is so minimal that without the reverse current surge from the condenser there is no spark.
    Dusty

  13. #13

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    Oct 2015
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    @Ridgerunner, you're awesome

    I do need to double check the pushrods just in case, but the thing runs so good and starts from cold so good that I was kind of thinking that wasnt it. \

    you suggested the condenser and I thought that may be it. I did a search and turns out that Condensers on airplanes are often subject to heat soak which causes a misfire or weak spark when heated up. Ordered a new one from Morris, fitted it and took it for a really quick run but seems to have sorted the issue. I need to take it on a longer shakedown where it heats up more but I am hoping that you just solved an issue that has been haunting me for 6 months.

    Thanks man, and also all that replied here. @DustyDave your Tractor problem and mention of heat soak definitely had me on the right track.

    Thanks all
    T

  14. #14

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    May 2015
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    "took it for a really quick run": So you don't know if you actually solved the prob or not?

  15. #15

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    Quote Originally Posted by docmel View Post
    "took it for a really quick run": So you don't know if you actually solved the prob or not?
    Yeah sorry I should have said that I took it for gas and to grab a drink, had to start it 3 times, and each time it started 1st kick. Which is a hell of alot better than it was doing before.

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