Try a new or known good spark plug. A spark plug can appear to work normally when tested for spark but fail under compression.

Also check the spark arrestor screen in the muffler.

Will try both of these suggestions and let you know you how it goes.

Try a new plug like ray said and quit using the starting fluid. Pour a little mix down the spark plug hole or the carb and hold the throttle wide open until it starts. Starting fluid is hard on small engines. Steve

Ok so I drained the old fuel, replaced the spark plug and checked/cleaned the spark arrestor screen, which wasn't clogged. Still the same result, no fire at all.

After checking the spark again, it was blue and consistent, but looked thin. Is it possible the spark is too weak and not strong enough to jump the gap at the spark plug? I checked the ignition unit for corrosion, and it looks new or almost new. Ground is good.

I've definitely got air, fuel and compression. Possible the spark isn't timed?...is there a flywheel key I should check?

There should be a key in the flywheel. You could try gapping the plug quite a bit less, if the spark was weak that might work. Check the plug wire for any worn spots that might be contacting metal. Did you dump a little mix down the carb or plug and hold the throttle wide open just to make sure it's getting enough fuel. Steve

Guys I'm stuck. I currently have the blower half disassembled, trying to to get at the woodruff key to see if it dislodged or sheared. I can't figure out how to get the flywheel bolt loose. Moreover, I'm not sure if I should even bother since it did run. I bought it over the winter and it was difficult to start but did run fairly well. It sat all winter and the first time I pulled it, it fired but didn't start. Since then, has not fired no matter what I tried.

New plug, checked ground, coil is spotless, and am getting decent blue spark. Air filter is pretty clean and no blockages in the intake. Compression measured 133. Drained old fuel, poured in fresh 50:1 mix with 89 octane, cleaned carb (looked good). I'm not totally satisfied that the fuel system is good as I've yet to check the filter and lines carefully. But I'm figuring that I prime with mix or starting fluid, I should get some sort of fire ya?

Any way I can confirm if the woodruff key is good without getting at it directly? If not, how do I get that flywheel bolt loose?

How wet is the plug after you try starting it, if soaked it might be flooded real bad. Try unhooking the lines to the carb then hold the throttle wide open while cranking. The needle valve might be leaking feeding more gas when your trying to start it. I really don't think it would be the flywheel key, that would be more common on a lawn mower when you run into a stump and it stops the engine real fast. Steve

Steve, thanks for the reply. I'm stuck and needing ideas right now. That makes sense to me. Bad flooding would prevent fire even with good spark, air compression.

Is it possible I'm getting spark at the wire, but not at the plug? The plug is brand new and gapped correctly at .025". Also, when I test the spark, I get a decent blue spark.

If your spark was weak it might jump across a plug out of the blower but not when in the blower under compression. Take a old plug and gap it 1/4" or so and see if the spark will jump that, it should assuming the old plug your using is good. You might want to try another new plug just to be sure. Steve

One trick I have used to get a small engine started so the problem can be found is to heat the spark plug tip with a propane torch and install it and try starting it. This will usually cause the engine to start. A common problem if the needle valve is leaking is the crank case will fill with fuel and then the fuel will evaporate leaving the oil to get sucked into the cylinder and cause hard starting.

Good Luck and keep us posted.

Ray

Ok, when I took the crankcase apart a fair amount of fuel spilled out. Also, when I had the carb apart, the inlet needle tip looked suspect. When I re-installed the needle valve and tightened the screw that holds the pin down, the needle didn't appear to unseat...if its too loose, the needle travels off the seat well but the pin partially dislodges. I tried to find a happy medium so I could see the needle unseat but the pin wouldn't dislodge.

To be honest, I'm just not sure if I put it back together right. Is the bulge in that pivot piece supposed to be facing downward (towards the spring) or upward? Will post again this weekend when I've got the carb kit installed. Thanks!

It's nice to know why it wont start!! The screw that holds the pin down has to be tight and the lever pivots on the pin to open and close the needle. I think the end of the lever that goes into the diaphram end should be about even with the carb body when the needle is closed. That lever has a little protrusion where the spring fits onto. Make sure the needle and seat are clean, one speck of dirt and you'll have flooding. Steve

Exhaust port needs cleaned out. Pull the muffler cover and then there are two bolts that hold the muffler to the cylinder. Ive seen more than one of these that have this problem. Its just part of a two cycle design. Since there arent any valves to completely hold the air and fuel mix into the cylinder, some spills out through the exhaust port and carbonizes on the hot metal. Use the starter handle to rotate the piston to bottom dead center, and then use a plastic knife or a stick to scrape out the carbon. Upon reassembly, check the screen thats in the muffler and make sure its clear. Use a lighter and a pair of pliers to hold the screen and turn the carbon to ash with your lighter. Re-assembly is the reverse of how you took it apart.
Good Luck,
Bob

So I got my carb rebuild kit and carefully installed it, but still no results. I also tested to see if the new spark plug was firing, and it does...though I can't confirm if it does so under compression.

Bob, thanks for the new suggestion, I'll will certainly try it. Probably won't get to it until the weekend, but will report back.