My Dyna needs some threads cleaned. I noticed my spark plug threads are a bit gunked up as well as the threads for my breather bolts. I have read that a thread chaser is recommended. Does anyone know the sizes needed for both these holes? I've been searching and haven't found any definite answer. I believe the breather holes may be 3/8 - 16 but not sure. Also, any idea where I would be able to pick the correct size chasers locally? Any help would be greatly appreciated!

 

First, assume you mean 2010 FXDC and not 2020 like the title says. Anywho, the breather bolts are actually 3/8 x 1.525. Spark plugs are 12MM x 1.25

 

Most auto parts stores will have an M12 x 1.25 spark plug/oxygen sensor thread chaser in stock.

 

All TC head breathers are 3/8-16 like you say.. Plugs 12mmx1.25mm as dawg says..

 

Yes 2010. Sorry I don't know how to edit my post. Had to order some online as nowhere local had what I needed in stock. Thanks for the quick replies guys!