pmags and prop kickback

[erich weaver]

My pmags have generally worked fine for me, but every once in awhile, I dont get an immediate startup for whatever reason, sometimes something as stupid as having not flipped the ignition switches on. The problem comes when I go for start try #2. Sometimes I get a prop kickback when I hit the switch. After severe cussing, I try again and everything has been fine - until now. Removed the cowl and spot checked everything the other day and found that the case on my starter (Sky-Tec model 149-NL) is badly cracked. More cussing.

Called up emagair this morning and talked to Brad. Apparently kickbacks are an occasional problem on aircraft with lightweight composite props such as mine - Whirlwind 200RV. The solution is to slightly adjust the ignition timing to 2-3 degrees past TDC. Wish I had known this before, but maybe this post will motivate someone else who has witnessed the occasional kickback to make this change now instead of experiencing a broken starter while far from home.


SkyTec says the most I will be out is $200, and I may be able to get full warranty coverage - need to check the logbook to see when the starter was installed. Im relieved about that.

regards

erich

[Toobuilder]

IIRC, there is a setting which allows a certain number of blades to pass before it fires. This only works on the first try though - so you have to recycle ignition power to reset the start delay feature.