1. Husqvarna Motorcycles Made In Sweden - About 1988 and older

Triggering Runtronic Ignition System?

Discussion in 'Vintage/Left Kickers' started by Carl Jespersen, Feb 2, 2018.

  1. Carl Jespersen Husqvarna
    A Class

    Husqvarna Motorcycle:
    Very proud owner of an 83 430WR !
    Any experience with Runtronic ignition systems?

    Got a 430WR which is now fitted with a Motoplat mini6 as the magnets fell out of the SEM more than 30 years ago! Bike was less than 3 years old at the time!

    My brother has a 430WR with a PVL internal rotor on it. Doesn't start very well. Some people claim PVL's are not recommended for bikes bigger than 250cc. WTF??
    He is 62, can only kick it so many times, LOL!

    I would like to replace both with Runtronic systems.

    --> The question I have is the trigger. How would a magnet be mounted to the crank? <--

    Could I use a Motoplat internal or external rotor?

    Or another manufacturer's rotor/flywheel?

    ANY suggestions, would be most welcome!
  2. visiteur1948 Husqvarna
    Pro Class

    Location:
    france Europe
    Husqvarna Motorcycle:
    husqvarna only
    colle-epoxy-bi-composant-poxymatic-alu-loctite.jpg

    SEM is very good but magnets ....!!

    sticking magnets SEM/AMAL with
    epoxy !no problem after !!
    :thumbsup:


    imagesCAF7UD64.jpg
    SAM_2536.JPG
  3. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    We had the same problem with the Husqvarna chainsaws when they used the SEM ignitions too the glue holding the magnets would chip. We would epoxy over the magnets. I guess it’s a ongoing thing with any SEM ignition.

    Some ignitions on the bigger bore bikes we can’t turn them over fast enough to make spark. The PVL is one of them it’s been said here. Maybe adding a compression release would help?
  4. jo360 Husqvarna
    AA Class

    Location:
    perth australia
    Husqvarna Motorcycle:
    1983 exc framed wr430 engine
    Other Motorcycles:
    ktm 520exc
    Put an electrexworld stator in my sem amal but still got a weak spark, i then fitted a cheapo coil and made my own cdi from a kit ($45) this altered the timing due to the new cdi picking up on the pulse coil output voltage earlier than the original cdi built into the coil.
    I had to redrill the stator mounting plate to get to where i could set the timing with a timing light safely.
    I removed the spark plug and used a drill to spin the engine with the tdc marked on the case and advance retard markers on the flywheel.
    Using the drill method nagates the chance of a kick back/broken cases scenario.
    Spark is now a strong blue and is a left leg start when hot using decomp and about the same effort as would be applied to starting a 125.
  5. Carl Jespersen Husqvarna
    A Class

    Husqvarna Motorcycle:
    Very proud owner of an 83 430WR !
    Thanks for the advice.
    I think i'm going to get an internal rotor, motoplat, PVL, HPI, whatever is cheapest.

    Then make a mounting plate for the sensor out of aluminum with slotted holes
    so I can rotate the motor with drill and use timing light to time.

    I looked through a some rotor listings looks like some KTM's use a similar size & taper but not many available used. About $80-90 for used one. (Gulp)
    Regards
  6. Carl Jespersen Husqvarna
    A Class

    Husqvarna Motorcycle:
    Very proud owner of an 83 430WR !
    Alan Greenfield is the contact for Runtronic units.

    He says they are triggered by a magnet 5mm in diameter, mounted on a 2" OD non metallic disc.

    After a LOT of research I've found the taper is 7 to 8 degrees, depending on how you measure it or where you get your info.

    A popular reamer for 4WD & stock car guys is 7 degrees and change.

    Going to use an aluminum disc 1/2" to 3/4" thick, mounted in metal lathe.

    Bore a hole with a chuck in the tailstock, switch to reamer, then chuck up an old crankshaft stub in lathe, mount disc on it
    tighten the nut & true up the OD. Done.

    Can anyone recommend a cheap waterjet shop? I don't really want to use a holesaw on something that thick.

    I'll keep you all posted.
    Thanks for an awesome forum!!
  7. Bryll Husqvarna
    AA Class

    Husqvarna Motorcycle:
    Some
    Other Motorcycles:
    Some
    I tried a Runtronic system on one of my bikes, didn't like it so I bought a system from Electrex.

    But, I made a "flywheel" of an aluminium disc for the Runtronic that I drilled a hole in for the small magnet.
    The magnet was secured with loctite.

    Keep in mind that the Runtronic system is developed for smaller petrol model engines or methanol model engines converted to petrol.
    I will retire my Runtronic, so if anyone want it just let me know and I put it in an envelpe.

    The system was used on a Yamaha SR500 engine