McCulloch MC200VS Leaf Blower Won't Crank

[phoneticsoft]

Hello forum!

I'm beating my head up against a wall trying to figure out why my McCulloch MC200VS Leaf Blower won't crank. Until a few weeks ago, it cranked up every time if I followed the instructions by priming it, putting it on full choke, pulling 3x, putting it on half choke, and pulling 3x or 4x. But now it doesn't even try to crank. I have already tried/done the following, not in this order:

• replaced spark plug
• verified that spark is happening by grounding plug while pull-cranking
• cleaned air filter
• removed air filter completely and tried to crank
• sprayed a little starter fluid into carb and tried to crank
• replaced carburetor completely
• replaced fuel lines
• replaced fuel filter
• held thumb over spark plug hole while cranking...seems to have compression
• removed spark arrestor (entire muffler) and tried to crank...I read those can be clogged but mine seems fine
• replaced gas/oil mixture with fresh

Same result every time. No start. What else is there to try?

Thank you in advance.

 

[bertsmobile1]

To run you need
Fuel in a ratio that can burn
An ignition source that happens at the right time
Compression

For 2 strokes, you have 2 compressions, primary ( in the crankcase ) & secondary ( in the cylinder ).
What most do not realize is with these tiny engines it is very easy to flood them, particularly when spraying starting fluid down the plug hole.

Now once a new plug gets wet, they will fire quite happily in open air but short down the insulator under compression pressure.

Mechanical things are the easiest to check so pull the starter off and check that the flywheel has not sheared the locating pin.
Even a cracked one can stop the engine starting.

If it checks out OK then heat the spark plug to a temperature that is too hot to hold in your bare hands.
Put a very small amount of starter fluid in the plug hole, replace the plug loosely and try to start the engine with the throttle wide open, no choke.

If you get nothing then there is a problem with the piston & rings.
When you had the muffler off did you turn the engine over and look at the condition of the bore & the piston ring ?