Timing light troubles.
Buy a pos if you want to. It's your money. Here's the one I have.
[ame="http://www.ebay.com/itm/USA-Vintage-Balkamp-Timing-Light-Sturdy-Chrome-6-12-Volts-/371169088059?pt=LH_DefaultDomain_0&hash=item566b66d23b"]USA Vintage Balkamp Timing Light Sturdy Chrome 6 12 Volts | eBay[/ame]
Was given to me by my auto shop instructor in 1983. He owned it since the 60s. It's hands down one of the best I have ever used.
Two things about timing lights. 1) Do NOT get a dial back piece of crappola. I don't care who makes it. Too much room for error.
2) Do NOT get a timing light that the wiring harness unplugs from the gun. They always work loose and fail to make good contact.
Don't waste your money. Get a good old, heavy METAL RELIABLE non dial back light. You'll be glad you did.