Retarded Ignition! help!

Discussion in '2-Stroke Engines' started by RMWdave, Jun 3, 2009.

  1. RMWdave

    RMWdave Member

    i turned over a chain locked happytime with a wrench on the magneto side of the crank. Due to chinese building ****, the magneto moved as the already loose nut and lockwasher bit into its side. you tell me

    magneto moved in direction of tightening. (clockwise)

    i see there is a woodruff key in it, but its definitely been retarded. the thing is gutless! wont go over a putt-putt speed.

    is there a way to fix this? i could use a crash course on removing it as well so i can cech the state of the key in case it just bent

  2. fastboy9

    fastboy9 Member

    Hi dave, I'm going to move this into the 2 stroke section as I'm sure you will have better results with it in there. Hope it gets back to its glory!

  3. DIYMark

    DIYMark Member

    Keys probably not bent, just a shoddy machining job.

    My engine looks like the crankshaft slipped when they machined the magneto keyway, as a result it was oversize and offered 20* play - this is a god send! Adjustable ignition.

    When I got my motor Ive full blown moddified it, port matched all ports, expansion chamber, custom intake, twin machined boost ports, matched and ported transfers, custom machined head - to name a few. But still The bike was gut less!

    Only thing is that it felt like it was struggling up the hills - ie too much load. And I dont think I put on like 50Kgs weight since my last MB so I was positive the ignition was way to advanced (compressing the power stroke). So, using this magneto play, I set the magneto to cross the "midway point" ~0.8mm BTDC with was using a CORRECTED compression ratio of 9:1, so if your running a complete stock setup or a setup with no compression mods set it to fire 1.5mm BTDC.

    Midway point is the imaginary centre line between the 2 coil tines, as the mag passes this the CDI fires - not 100% accurate but what else can you do with these nasty ignition setups.

    It "set" mine by tightening the nut a little then putting rope in the spark hole (stop piston) then grab the magneto on the flat with multigrip pliers and turn it. Once set, tighten the nut up fairly tight ( I got a different nut because the chinese one will stripp before any reasonable torque is applied, I used a stainless M8 X 1.00mm)
  4. RMWdave

    RMWdave Member

    ah what an idea! haha thanks alot i forgot about the rope stop.
    im **** sure its been retarded, does it sound right? magneto turned in direction of rotation? it sounds like the exhaust is baffled up, has no power. it starts easier. and so on
  5. DIYMark

    DIYMark Member

    If its been tweaked so that the magneto is moved "into" the direction of rotation the ignition is to advanced. If it were tweaked backwards (to the direction of rotation) the ignition would be retarted.

    Most likley its too advanced as the mag would turn clockwise (into direction hence advanced) when the bolt was done up for assembly in the factory.
  6. RMWdave

    RMWdave Member

    wow ouch.... not good.
  7. RMWdave

    RMWdave Member

    thanks alot for clearing that up.
    ill have to tweak it back a bit with something before it does some serious damage.
  8. Dave,

    You twisted the crank while messin' with the chain.

    You will be very lucky if you can straighten this out! The crank is a small diameter at the magneto side.

    It is unlikely that you will be able to twist it back.