Static Cub magneto

[Old Man]

Attempting to static time the magneto on my 1952 Cub. I’ve completed the steps exactly as described in the service manual and have watched YouTube videos as well. Everything goes according to plan until the “2nd snap” of the mag happens between the timing marks on the crank pulley and I haven’t rotated the mag away from the engine yet. What is happening? What am I doing incorrectly? Thanks

[Jim Becker]

Your governor gear is probably one tooth off on timing. Take a look at this thread, about the 6th post into it.
viewtopic.php?f=1&t=110756&p=880139

[Old Man]

Thanks for your quick reply. I suspect that is the case. The previous owner removed the mag coil and replaced it with an external coil and voltage regulator. Probably due to a timing error on the magneto. How difficult will it be to verify that the timing marks on the idler gear and drive gear are aligned correctly and to make adjustments if necessary? Is it possible to do w/o removing the radiator?

[Bill V in Md]

How difficult will it be to verify that the timing marks on the idler gear and drive gear are aligned correctly and to make adjustments if necessary? Is it possible to do w/o removing the radiator?

Yes, this can be done w/o removing radiator. First, bring the ignition system to TDC on the compression stroke of #1 cylinder. Then remove the magneto. It will be difficult to see the timing marks with the governor seal in place, especially if the marks have not been previously marked with white fingernail polish or something similar. However, it is possible with a good flashlight. If you discover that the idler and governor gears are not timed (meshed) correctly, you will need to also remove the governor. It will be necessary to disassemble some of the governor linkage to do this. This can still be done w/o removing the radiator. Then just put a white mark on the timing marks of the idler and governor gears, and re-insert the governor gear correctly, in the proper location. After reinstalling the magneto it will be necessary to go through the static timing process.
Good Luck

[Glen]

Hi,
Below is a post I wrote on telling how to remove the governor, you have to remove some of it's linkage to remove it.
The post is my 3rd post on the page.

viewtopic.php?f=1&t=110942

Below is a post I wrote on showing the Idler gear and governor gear timing marks.
It has info about replacing the oil seal between the governor and the magneto, which you could do if it is old. TM Tractor has a new seal.
My post is the last one on the page.

viewtopic.php?f=1&t=110067

[Old Man]

Hey guys. Thanks for all your help. I removed the governor and assured that the timing punch marks aligned appropriately. Replaced the governor and magneto timed perfectly. Another problem solved.