What is the fuel to oil nixture for my attact II (200mph.)leaf blower

Most 2 cycle engines need at least 90(ish) psi to at least run. Most need more to run correctly.

the owners manual, available online has some trouble shooting tips...

I mix mine 50:1

Are you sure this is a four stroke engine, i thought all the small blowers were two strokes in which case there is no oil in the crankcase, the lubrication is mixed with the fuel

50:1 regular gasoline(fresh).

Two-stroke oil with a 50:1 (Gas:Oil) mix ratio is required for the Husqvarna 125B leaf blower. Using the wrong oil or improper mixture ratio can drastically affect the performance of the leaf blower.

check age of gas. Cannot be more than 30 days old.
Make sure to use fresh gas w/synthetic 2-cycle oil @ 40:1 ratio (1 gal.) Gas to 3.2 oz. Oil). Do not use old or stale oil/gas mixture. Always use the proper oil/gas mix. If you do not, your engine will suffer rapid, permanent damage.May need to clean or replace carburetor.

if you have no fire to the plug of course you have replaced the plug but now find the kill switch wire disconect it then see if it fires if it doesnot fire it is the ign coil

Yes it will use a fuel mixture of 40:1(3.2 oz of two cycle oil to 1 gallon of gas). Any fuel sitting over 30 days now is considered bad fuel. All the manufacturers schools this year and told us this. We are finding it to be true.
Good day.

it might have vapor lock, try removing the spark plug and spray a little penetrating oil into the cylinder, let it sit for a couple minutes and try pulling the cord again with the spark plug still off.