Autosport Labs

Of course you know about where cylinder #1 should show on the timing mark. The others should be delayed a known amount. A good first check, is use an inductive timing light on every plug wire, to make sure the spark happens about the right time for that cylinder. The timing mark will be illuminated ...

There are a couple problems with putting the VR beside the wheel, instead of outside it. Any side to side wobble & engine end play will directly influence the waveform, as opposed to no effect outside. It appears to me that the gaps from the side aren't as well defined magnetically, because the ...

My guess, you have a defective coil, or possibly a poor 12V power connection. Bruce Roe

The actual coil voltage rises until the spark gap path arcs over. So the coil itself doesn't really determine it. A wider plug gap, or a fouled gap could do it. My guess is, the insulation on some of the wires is better than others. Bruce Roe

The picture MEGAJOLT LITE JR V4.X CONNECTOR PINOUT is looking at the connector from outside the case. Notice the screw heads at the corners. The pin at lower right is +12v; you could verify this by tracing it back to the + (9V battery) test point on the circuit board. Incidently that is connector pi...

My experience is, tin plate connections at logic levels will fail some day. My fixes are to either solder things, or use gold to gold connectors. A chip can be placed & soldered into a "carrier" with gold plated pins. That may be plugged into a connector with gold plated pins. One proc...

Guess I should have said, this was run on the bench using my trigger wheel emulator circuit. And up to 4 coils/8 spark plugs. That makes it easy to get any coil config desired, no hot screaming engine. Bruce Roe

alhbln, Thanks for the comment. My objective here was to find out how much DC current my wimp alternator must supply to keep up. This was a new load on a rather small source, 'cause the old ign ran off flywheel magnets, no battery. I put a pretty heavy filter on the input to smooth the spikes, and m...

TUNING PLAN improve mid range torque lower possible idle speed reduced fuel consumption at part throttle with more advance ease starting with reduced cranking advance MJLJ-V4 TUNING PLAN use manual ADVANCE knob to shift entire map up to + or - 12 degrees after best advance found, modify ignition map...

There is a very basic reason, why 2 coils can't be driven in parallel by the same driver. When the current turns off, voltage on all windings will rise ONLY until current flows through ONE pair of spark plugs (ignition + waste). At this point that circuit voltage will drop, as will voltage on ALL th...

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The picture looks like the trigger wheel is on the outside of the harmonic balancer. On several of mine, the old rubber has let the outside slip, loosing the timing mark. But in this case, the engine would stop. Bruce Roe

I sent a file to AUTOSPORTS LABS, which reverses the readout and properly scales it to read degrees F when using the very common (2 wire, EFI) coolant temp sensor. Bruce Roe

I ran a curve to see what the battery current would be. With an efficient electronic dwell, its pretty much proportional to number of ignition coils driven times rpm. There is a base current of around .12 amp with the engine not running, which increases to maximum of .22 amp by 1000 rpm. Each coil a...

Ok, its running & partially tuned. Already there is a big difference in performance, from the old fixed advance to an optimized spark advance. 100 hours a year running this engine, and 22 degree fixed ignition just wasn't doing it. The odd fire twin is running an MJLJ-V4 and an EDIS setup, but o...