George see my post #3 and his reply #8

Would it hurt to see if the engine will hit (don't run it) with the muffler off? Can't say I've ever tried such, but have seen the "spark arrestor" screen in older machines plug up as well as 3-4 times encountered dirt dobbers building a nest in the muffler.

It’s not a bad idea John but I believe the echo has the spark arrester screen screwed right on to the outlet of the muffler and would be obvious to see if clogged but hey I’ll believe anything as I see weird results and symptoms of no starts every day.

Exhaust is wide open like a strippers legs on pay day. Including the arestor.

The arrester is not attached, I took it off, it was a little rusty but open and I cleaned it up with a wire brush.

Exhaust port is wide open and clean, it is the in the video clip I attached in a previous reply.

Yes I saw this reply much earlier in the thread? I was responding to John halls idea that it might be a clogged muffler stating that you already answered that as well....

How are you checking spark, plug removed from the head and laying it on the motor, or is it not.

A big 10-4 on wide open :biggrin2: :biggrin2:

So it has spark, fuel, air, and the exhaust is not plugged--correct? I forget, compression test results? This brings timing front and center does it not? Also--here is one that drives folks nut on a 2 cycle---bad crank seals. I had it to happen on an OLD 041AV Stihl chainsaw. Buddy loaned me his "test kit", but still think I had to modify/make a block off plate. Can't remember but I believe I plugged the exhaust and pressurized the intake, then later pulled vacuum on intake? I've got a really old Echo issued vacuum tester that I used in addition to my friends. I wound up tearing that saw all the way down---everybody should do that once. I don't think there was anything left bolted together except the carb (I had already put a kit in that). There is a reason every lawnmower shop has a big pile of 2 cycle products in the scrap heap.