CHOP CULT HOME
Email Password
Search
Page 1 of 2 12 Last

Thread: Magneto issue

  1. #1
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default Magneto issue

    So I'm having a bit of a issue with my magneto and I'd like to get someones point of view on it.

    Thing is I have a MM74 Morris Magneto. I ran it on my dual plugged 74" cone shovel, with the basic upgrades like higher compression, Leineweber cam etc., a couple of years back with no issues. Good spark, always started first or second kick.

    Now I have this stock bore stroker that I thought I'd put it on, since that mag was just laying on the shelf.
    This motor is a 4 5/8" stroker, Leineweber L3S cam, Super E, dual plugged and so on. Nothing radical really.

    So I put the mag on it, timed it and went to kick it over and nothing. I had been running Morris' MSF wires so I used those initially. Then tried just normal wires, using only one spark plug per head. Same, just nothing.

    Eventually I put wires in each magneto terminal to see if I get a spark there. Best I could get kicking it over was a spark between the two with maybe a 1/4" gap between the two. Anything more than that there was nothing. Took the mag off and tested it on the bench by turning it using a hex key. Then I could easily get the spark to jump an inch.

    From all this my conclusion is that I am not able to kick it over fast enough to create a spark strong enough to get the thing started.

    Any ideas what could be done or am I missing something really obvious here?

    And before guys start telling me to go back to whatever ignition I had before I put the mag on. It has gotten to a point where it is not about what is easiest or best, but it has become an obsession to figure out what the hell is going on with this thing.
    When I figure that out I may well go back to what I was running.

  2. #2
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Oct 2012
    Posts
    1,607

    Default

    Quote Originally Posted by andri View Post
    So I'm having a bit of a issue with my magneto and I'd like to get someones point of view on it.

    Thing is I have a MM74 Morris Magneto. I ran it on my dual plugged 74" cone shovel, with the basic upgrades like higher compression, Leineweber cam etc., a couple of years back with no issues. Good spark, always started first or second kick.

    Now I have this stock bore stroker that I thought I'd put it on, since that mag was just laying on the shelf.
    This motor is a 4 5/8" stroker, Leineweber L3S cam, Super E, dual plugged and so on. Nothing radical really.

    So I put the mag on it, timed it and went to kick it over and nothing. I had been running Morris' MSF wires so I used those initially. Then tried just normal wires, using only one spark plug per head. Same, just nothing.

    Eventually I put wires in each magneto terminal to see if I get a spark there. Best I could get kicking it over was a spark between the two with maybe a 1/4" gap between the two. Anything more than that there was nothing. Took the mag off and tested it on the bench by turning it using a hex key. Then I could easily get the spark to jump an inch.

    From all this my conclusion is that I am not able to kick it over fast enough to create a spark strong enough to get the thing started.

    Any ideas what could be done or am I missing something really obvious here?

    And before guys start telling me to go back to whatever ignition I had before I put the mag on. It has gotten to a point where it is not about what is easiest or best, but it has become an obsession to figure out what the hell is going on with this thing.
    When I figure that out I may well go back to what I was running.
    Big incher with a mag requires solid core wires non resistor plugs and close gapped plugs.Or an impulse unit.
    Dusty

  3. #3
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2017
    Posts
    2,537

    Default

    seen this:

    Retro Tech – Installing A Morris Magneto on a Shovelhead

    "As for those easy starts, modern Morris mags use Morris’ balanced impulse coupling system, which works with both kick and electric start setups on any size motor. When I used to be a piston-engine aircraft mechanic, the dual magneto ignition systems on those engines always ran impulse couplings to facilitate easy and dependable starts. When the starter, be it kicker or electric, turns the engine over, the magneto’s rotor also spins to generate the power needed to fire the spark plugs. The faster the magneto’s rotor is spun, the stronger the spark produced. However, the most critical time is just before the ignition system’s triggering device breaks the circuit, which is when the high-voltage from the ignition coil is sent to the spark plug. To increase the power of the spark, the Morris impulse coupling, which is spring loaded, winds up and then snaps forward just before this important point of the magneto’s rotation to quickly spin the magneto’s internal generator. The result is an intensely hot spark; one much more powerful than what you could get by just using your leg or even an electric starter..."

    https://www.aimag.com/retro-tech-ins...-a-shovelhead/


    Have you seen this 2018 Thread: Help w/ Morris Magneto MM74L on Shovelhead

    http://www.chopcult.com/forum/showthread.php?t=51926

  4. #4
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    May 2017
    Posts
    288

    Default

    As Dusty mentioned,

    Try closing the gap on your plugs a little, solid core as a rule are always required. Maybe see if you can search what other people use, plug wise.

  5. #5
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Thanks for the link.

    Forgot to mention that the magneto only has a few thousand miles on it, but has been sitting on a shelf for a bit.
    I’m running solid core wires and non resistant Autolite plugs.

    I’ll have a look at the points, try to deglaze and gap them correctly.

    What really bothers me is that I seem to not be able to spin the mag fast enough while on the bike to get a proper jucy spark.
    But I’m getting it while bench testing it.

    Maybe the way to go on a stroker is the M5. I’ll give this a few tries before giving up on it.

    Also worth mentioning is that before installing the mag now the bike started easily and has no intake leaks and the carb is in good shape.

  6. #6

    Join Date
    Feb 2013
    Posts
    123

    Default

    There are 2 starter ratchet gears, 14t and 16t, the 14t will give a better kick start ratio. Information from a Morris Magnetos instruction sheet from around 1980. Good luck!

  7. #7
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Quote Originally Posted by pan620 View Post
    There are 2 starter ratchet gears, 14t and 16t, the 14t will give a better kick start ratio. Information from a Morris Magnetos instruction sheet from around 1980. Good luck!
    Now we’re talkin’!
    Excellent, thanks!

    Just ordered one. Hope the 14 tooth gear and a longer kick arm will get this thing going enough to light this mag up.

  8. #8
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Aug 2013
    Posts
    344

    Default

    XLforum is a wealth of information about magnetos. There's a ton of great threads on there about getting them tuned up. Usually not more than just taking it apart and cleaning it will make a huge difference. I did that on mine, which is very lightly used and it made a lot better of a spark. Rebuiltmags is a great site for condensors and points. Same as morris sells but cheaper.

    That said, I have a 4 3/4" stroke panhead with a mag. After a lot of experimenting and talking to to Dave at morris, try this:

    Come up on the rear compression stroke. (Fat lobe if you have a clear lid, but you can also feel it while kicking. If we look at it as the rear firing first, the crankshaft rotation between the rear firing to the front is far shorter than the front to the rear, if that makes sense)

    Bump it thru compression, just barely. Real carefully. Now, dont ratchet it back to til you feel compression again(front cylinder). Instead, right after you bump it thru, let the kicker go all the way back to the top, hoist your weight up and bring it down on the kicker. There will be no compression so you cant put any weight on the kicker until you are ready to kick. Make sure your knee is bent because the kicker will have almost no resistance.

    It's a little clumsy to do the first couple times, but you'll figure it out. I usually straddle the bike, or put a knee on the seat. That way you are starting the piston stroke on the way up rather than right up against compression. The piston will have more speed and it will go right thru the compression stroke, fire, and hopefully have enough speed to get you to the rear cylinder(longer gap between firing than rear->front) if it doesn't light.

    This is what I learned from people with similar setups. Hopefully it all makes sense, and it will feel really weird until you get a handle on how to do it. But you can get the motor to spin way faster once you figure it out.

    Also, don't flood it hahaha.

  9. #9
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,286

    Default

    Man, Snap Mag is the way to go ... But dang they are up there in bucks ... !!

    I wonder if Morris would take your Mag and install a impulse base on it ... ??
    That way it would be affordable ....

  10. #10
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Quote Originally Posted by gorgeous View Post
    XLforum is a wealth of information about magnetos. There's a ton of great threads on there about getting them tuned up. Usually not more than just taking it apart and cleaning it will make a huge difference. I did that on mine, which is very lightly used and it made a lot better of a spark. Rebuiltmags is a great site for condensors and points. Same as morris sells but cheaper.

    That said, I have a 4 3/4" stroke panhead with a mag. After a lot of experimenting and talking to to Dave at morris, try this:

    Come up on the rear compression stroke. (Fat lobe if you have a clear lid, but you can also feel it while kicking. If we look at it as the rear firing first, the crankshaft rotation between the rear firing to the front is far shorter than the front to the rear, if that makes sense)

    Bump it thru compression, just barely. Real carefully. Now, dont ratchet it back to til you feel compression again(front cylinder). Instead, right after you bump it thru, let the kicker go all the way back to the top, hoist your weight up and bring it down on the kicker. There will be no compression so you cant put any weight on the kicker until you are ready to kick. Make sure your knee is bent because the kicker will have almost no resistance.

    It's a little clumsy to do the first couple times, but you'll figure it out. I usually straddle the bike, or put a knee on the seat. That way you are starting the piston stroke on the way up rather than right up against compression. The piston will have more speed and it will go right thru the compression stroke, fire, and hopefully have enough speed to get you to the rear cylinder(longer gap between firing than rear->front) if it doesn't light.

    This is what I learned from people with similar setups. Hopefully it all makes sense, and it will feel really weird until you get a handle on how to do it. But you can get the motor to spin way faster once you figure it out.

    Also, don't flood it hahaha.
    All right. That makes sense! Looking forward to give it a try.
    Guess cleaning the mag is worth doing. At least I have the time now before spring.
    Thanks!

    Quote Originally Posted by Dragstews View Post
    Man, Snap Mag is the way to go ... But dang they are up there in bucks ... !!

    I wonder if Morris would take your Mag and install a impulse base on it ... ??
    That way it would be affordable ....
    It would be great to trade mine in or have it upgraded or something. But what really kills it on top of everything else is the shipping from up here and import fees when it comes back.
    So I’ll give this a try for now.

    Also on top of the 14 tooth gear and a longer kicker shaft I ordered a .26 microfarad condenser. Don’t really know if that will do anything. But worst case I’ll have a spare one.

  11. #11
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,286

    Default

    Quote Originally Posted by andri View Post

    It would be great to trade mine in or have it upgraded or something. But what really kills it on top of everything else is the shipping from up here and import fees when it comes back.
    So I’ll give this a try for now.
    There may be a way around that ...

    Here's whats going on ...
    Soon will have a stroker kit together to send to Reykjavik Iceland ..
    I could put the Mag in that box with the crank ....

    Just a thought ...

  12. #12
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Quote Originally Posted by Dragstews View Post
    There may be a way around that ...

    Here's whats going on ...
    Soon will have a stroker kit together to send to Reykjavik Iceland ..
    I could put the Mag in that box with the crank ....

    Just a thought ...
    That’s one way around it.

    How is it, are the mm74 and the g5 bases interchangeable? That is are the mag heads the same in the two?

  13. #13
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,286

    Default

    Looks to be....

    But I'm not the one that can say for sure ...
    I'm a dealer for Morris Mags, tomorrow I'll get the low-down from Dave Shaw ...

  14. #14
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Oct 2012
    Posts
    1,607

    Default

    Always check each new batch of plugs with an ohm meter. It realy fucks up junp start mag bikes when they decide to change to resistor without notice. Bout 20 years ago NGK changed a non resistor plug to resistor that lots of Indian 4s with mags used sure made them miserable to start.
    Dusty

  15. #15
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2010
    Posts
    12,286

    Default

    Not that cost effective to do a swap ...
    Reason being just the housing can be reused cause the rotation runs backward and all the guts is different ...

    I would suggest load yours on eBay and save up the rest for the G-5 ....

    Or as Tattoo would say .. Go back to battery ignition. (He like points, they're cheap) .. !!
    Last edited by Dragstews; 03-19-2020 at 12:10 PM.

  16. #16
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Quote Originally Posted by Dragstews View Post
    Not that cost effective to do a swap ...
    Reason being just the housing can be reused cause the rotation runs backward and all the guts is different ...

    I would suggest load yours on eBay and save up the rest for the G-5 ....

    Or as Tattoo would say .. Go back to battery ignition. (He like points, they're cheap) .. !!
    Ah ok. Thanks for checking.

    I’ll wait for the parts to come in and see what that does. If not I might try to work something out to upgrade for a G5.

    I can always go back to what I had in the meantime. A magneto is just much cooler. As long as it works, that is.

  17. #17
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2014
    Posts
    1,451

    Default

    Wondering where you bought that 14t kick gear from ?

  18. #18
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Quote Originally Posted by 47str8leg View Post
    Wondering where you bought that 14t kick gear from ?
    I got it from W&W in Germany. They ship cheap and fast to us up here.

    also I put in a new Condenser and got a fat juicy spark and the bike started up right away. Going to set the timing for the dual plugs using Morris' MSF wires. See how that goes.

    Still haven't swapped the gear, but will do that in the coming days for hopefully a easier kick through.

  19. #19
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Mar 2012
    Posts
    683

    Default

    Also looking at ebay there seem to be plenty available there.

    https://www.ebay.com/sch/i.html?_fro...arley&_sacat=0

    Part number is 33430-59

  20. #20
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2014
    Posts
    1,451

    Default

    Quote Originally Posted by andri View Post
    Also looking at ebay there seem to be plenty available there.

    https://www.ebay.com/sch/i.html?_fro...arley&_sacat=0

    Part number is 33430-59
    Most of that is Chinese garbage. Do you know where W&W Cycles are made ?

Share This



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Log in

Log in