You could use the fancy and expensive Stihl tool to set the gap or you could fiddle around with a feeler guage but a plain old business card between the flywheel and the pickups works just as well. Business cards are cheap....grab 'em off the bulletin board at the grocery store.

Using an index card is a good rule of thumb! I did see the next 2 specs when I ran a search on "Stihl 029 coil air gap".

1. The Magneto/Coil is set at .015in from the Flywheel.

2. It is to be set at .2-.4 mm or .008"-.016" .

3. Are there points to inspect and a gap to check? Good Luck! loger

I have the Stihl tool and if memory serves me(it's in the shop) it mics out at .014" and business cards average around .015". I just mic'd out a few index cards and they mic at .008".

Stihl makes different tools of this sort for different model saws but to my knowledge the only difference is the size of the radius to fit different diameter flywheels, the design of the tool is a piece of radiused stanless steel with a small plastic grip on the top which aids in removing the tool once the gap is set. The price for this tool as are the prices for nearly all Stihl tools, is stupid. You don't need it.

Business cards work. I've done lots of them.