Stihl BG 55 blower won't start

[vettman]

Here's what I've done so far: verified that the ignition module/coil is working; verified the start/stop switch is working; installed new plug gapped at .02"; installed new air cleaner; cleaned spark arrestor (it was pretty much pristine even after 9 years of use, thanks to all the operating time at WOT). It has been suggested that the flywheel pulley key may have broken or become dislodged, and the timing has slipped. Is there any way to verify that the key is missing without pulling the pulley? The pulley nut is holding the pulley to the crankshaft tight enough for the starter cord to crank the engine. Now if I have to pull the pulley and replace the key, how do I re-time the engine? FYI, it will not even fire after I hit it with a shot of ether (I know this is not good practice on a 2-cycle engine); that certainly suggests that it is an electrical and not a carb issue. Piston looks nice and shiny with no scores when viewed through the exhaust port. I would certainly like to get it running again, so any suggestions for what to do next would certainly be appreciated.

Thanks

 

[EngineMan]

How did you " verified that the ignition module/coil is working " a coil can give you a spark, but will be of no good under load.

 

[DaveTN]

I hate working on electrical as compared to mechanical woes. How did you test the coil? Did you ground the plug and pull the engine over to check for spark plug firing outside the engine? If it won't get fire outside it won't get it inside. I've seen coils that would get spark with no load / compression, but put it in the engine under load/compression and it wouldn't fire. Plug wet every time. Also seen spark plugs do the same way..with a coil good, the spark plug won't fire under compression. Coils can ground out going to the kill switch too. Sometimes the high energy plug wire can short out if the shroud cuts into it. Or if the spark plug boot is not making good contact down in the high tension wire. Seen that happen several times. Good Luck with it.

 

[Parkmower]

Rings could be shot not building up enough compression.

And re-timing is just replacing the sheared key in the key way and thats it.

 

[BWH]

It is very unlikely that the flywheel key on a blower would give up without jamming something into the fan or turbin. It sooner would be a fuel issue I understand you gave it some ether but I have been dissapointed with the ether made today it just don't have any kick and I have failed using that test. If the compression feels good when you pull it slowly I would suggest 4 - 5 drops of fresh gas in the spark plug hole then quickly replace the plug and give it a spin, this will rule out fuel problems. After 9 years fuel lines have been known to get hard and split causing air to be sucked into the fuel line. If that don't give any results Dave's ignition theory may be correct.

 

[Fish]

Try a brand new plug, don't mess with the gap either, see what happens.