Ariel Owners Motorcycle Club

Does anyone have a circuit diagram for a diy magneto timing light?

Les

Here is a link to a site which has a circuit diagram

http://www.gasenginemagazine.com/gas-en ... timer.aspx

I was going to knock one up but struggled to find the correct type of transformer. Instead I got a cheap £2 3 volt buzzer from ebay and wired it in series to an AA battery and two leads with crocodile clips to connect to the points and mag body. When the points are closed the buzzer sounds, when they open there is still a circuit through the magneto primary winding but the increase in resistance causes the tone of the buzzer to change. Once you have heard the tone change a few times you can very accurately determine when the points open. I find it better than having to watch a lamp as you can concentrate on the mag

These guys do a ready made timing light http://www.themagnetoguys.co.uk/Static_Timing_Light.php

Update: Just found this PDF which shows how to make one...
Cheers
Alan

You would be better to use a cigarette paper or a thin shim, and use the point where you can just withdraw it. Putting power through the primary can knock the magnetism around. I know there is a light in the circuit, but accidents can happen and the full 12 volts will alter the works. (Ask me how I know). IF you can remove the centre screw and the rotating mechanism stays in the taper you are safe with the light and battery. Nev

I need one of these.

Will Rizla go out of business?

I think the buzzer and single 1.5 volt battery is a pretty safe bet. I have tried isolating the center screw, and also using a nylon screw whilst setting the timing, but the points mechanism always seemed to move a bit when I put the metal screw back in and that altered the timing. The 'shop bought' boxes should be safe to use.

Here is a video of my Buzz Box working (turn your sound up). You should be hear the tone change which occurs at the instant the points seperate.

I bought an induction magneto timing box from an aircraft tool supply house in the USA called Action Air, $42 USD and made for purpose with light and buzzer. Nice tool for the workshop.

Frank

I think Rizla is more precise.

The flat face cam magneto is very sensitive to end float variation of timing. Ensure bearings are adjusted accurately. Backlash in gear driven magneto engines needs to be allowed for. (Load against drive direction) Nev

Thanks for the replies, I will have a go at the simple buzzer method though my level of frustration at having a non starting basket case has diminished as I finally got it going yesterday, so the feeler gauge method has worked for me. Incidentally the difference between starting and running and coughing and spluttering turned out to be a partially blocked pilot jet, did not enjoy drilling out the blanking plug to get at it, but it worked.