Timing a Tomos A3

Tery Smith /

Hello, everyone. I am a new member to the group and a new owner of an old moped. I was given a 1986 Tomos Golden Bullet with an A3 engine. The ignition was full of salt water, so I had to completely dismantle it to clean the crud out. I didn't realize the stator plates were adjustable, so I did not mark them when I took it apart. Does anyone have any information on how to set the timing? There is only one mark on the flywheel that I can find. It is ZEM with a line above it. I think it is the timing mark, because of it's relationship to TDC, but I don't know what to align it with on the body of the bike. I have a timing light that I can use, if only I knew what to do. The bike runs fairly well, I just want it to run as best as possible.

Thanks in advance for any help.

Re: Timing a Tomos A3

Hi Tery

I have a good start for you.

You have a strobe light?... Good... then do this.

First set the adjustable stator to the "center" of its adjustment by eye.

Find the TDC mark on the outside of the flywheel.

Then use a scale or tape measure and make another mark.

The new mark should be 3/4 of an inch to the left of the TDC mark... (yes... the flywheel is round and the ruler is straight... so just 'roll' the scale around... make the new mark)

Take a coat hanger and attach it to the bike somehow so that it lines up with the TDC mark when the piston is at TDC.. (use a screwdriver in the sparkplug hole to find TDC)

When the piston is at TDC... bend the coathanger till it lines up with the TDC mark when the piston is at TDC.

Now start the bike up and use the strobe light (powered by a car battery)... to see if the new F mark you made lines up with the coathanger... If it doesn't... you will have to loosen the stator plate up and rotate it and try again.

Re: Timing a Tomos A3 (FRED)

Hey Fred, will that be the same on the A-35 engine? Doug D.

Re: Timing a Tomos A3 (FRED)

I made a guess there Doug D.... (and Tery)

Measure the diameter of your flywheel.

If your flywheel is 4.5 inches diameter... then you can use that number.

(I made the assumption that all Tomos motors use the same dia flywheel)

Re: Timing a Tomos A3 (FRED)

Thanks a lot Fred! Doug D

Re: Timing a Tomos A3

Terry Smith /

Fred, thanks for the quick response. I will try it as soon as I get off work today. That is quite an ingenious method that you recommend. Once again, thanks and I will report back on the results.


Re: Timing a Tomos A3

chris griswold /

get a pic of ur ped

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