Timing on Motomatic 60cc Batavus M48

Dincus Dunkus Douglas /

Hey y'all, I'm very confused. Put the motomatic kit on my Starflite, and I finally got her running the other day, but it was running backwards. A little research and removing the rotor I saw the key was sheared and gouged the rotor, probably made the timing way the eff off. No idea when I did that little number on it. But anyway got a new key and magneto, reinstalled, and now I'm trying to adjust the timing. Already set the points gap.

My problem is that when I set the motor position to ~20deg BTDC (a good starting point as I've read, though nobody talks about the 60cc kit timing), my points are just starting to close and I believe per my manual that they should just be starting to open at this point with clockwise motion. See first image, with key position at almost 2 o'clock and points at 12 o'clock. This is ~20 BTDC, and the bulge on the rotor that opens the points is centered on that key, so you can imagine this is the tail end of open points. The 2nd image is the position at which the points just start to open, which is like, idk 90deg BTDC. So like is my stator upside down or something? In the Bat manual the stator is positioned such that points are at 12 o'clock, and when I had this all stock I believe it was situated like that as well.

Such confusing. Much misunderstanding.

20deg BTDC.jpg
Points opening, 90deg btdc.jpg

Re: Timing on Motomatic 60cc Batavus M48

Dincus Dunkus Douglas /

I may have figured it out, for anyone who runs into this. The relative clocking position of the woodruff key slot to the timing "bulge" that pushes open the points is different on these two rotors / flywheels / magnetos. So the one I bought cannot possibly work for timing the m48 - the bulge/key positions relative to each other are fixed.

The stock m48 Bosch magneto I have is a 6V22-5/10W, and originally I thought that's all I needed to know. Turns out that serial or part # that is stamped on there is significant too. My stock one says 0 212 124 041, and the one I got from Treats (says for puch but also Bats) has 0 212 124 039 - you can see it on the images below. There are other numbers stamped on these rotors, but I think it's that one and not the others.

Anyway I think this number might indicate the relative clocking position described at the top. So on the 039, they're inline, on my 041 (the original) they're about 90deg offset. In summary, you need an 041 I think, and looking at other supplier images that seems consistent.

I just bought another rotor off a m48, and per the image it's an 041. I'll update if this sorts it.

Re: Timing on Motomatic 60cc Batavus M48

todd amundson /

Hey I like this a lot. I just had a E50 come in running with a counter clockwise ZA50 flywheel on it that had a key in it. I have no clue how it ran. I ditched it for the right one and it’s running as it should. If you’re interested in getting rid of that Bosch E50 flywheel I’m interested. Thanks for the post!

Re: Timing on Motomatic 60cc Batavus M48

Dincus Dunkus Douglas /

Glad it was useful to someone other than me. You know I was just going to return the flywheel back to treats, sorry but I'm not sure it makes sense to sell it straight to you, but seems like they have plenty in stock.

I put on the new + correct rotor. I have still a variety of other stuff to do to get things running, but I did the timing and geometrically all seems good with the universe.

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