Husqvarna 440 e II won't run.

[Happster]

I have a Husqvarna 440e II that just has me stumped. (pun intended.) It will start after priming then cough and die, sometimes with a backfire. Everything points to fuel, or an air leak. I usually don't just throw parts at something, but I lost my *poop* trying to figure this one out. Here is what I have replaced, all with zero change:

New crank case gaskets and crank seals
New carb (twice) and intake boot
New fuel lines and filter
New primer bulb - it is priming beautifully
New cylinder and piston/ring
New coil
New magneto

Adjusting the China special carb did nothing, so I replaced it with a new OEM one and zero change in behavior. (My carb adjustment tool does not fit the new carb, but I highly doubt it's a carb adjustment.) I sprayed some starter fluid directly into the intake port with no carb or intake boot on at all, and it still didn't fire right up. I'm getting a beautiful spark. If I prime it, it will start and run for a few seconds, then just die. Exhaust port crystal clear, muffler clean. Ran the same with the muffler off. Absolutely baffled. The only thing i have not replaced is the crank and connecting rod assembly, but it seemed fine. Could it be geeked and throwing off the timing? Thoughts appreciated.

 

[Bob Hedgecutter]

Wow, thats a pretty long list of parts chucking.
About the only thing you have not covered is timing- you need compression, spark, correct air/fuel mixture reaching the combustion area and correct timing of the spark.
That would be my first check- confirm the key is still intact on the internal taper of the flywheel and the keyway cut in the crank stub is undamaged.

 

[Happster]

.

Wow, thats a pretty long list of parts chucking.
About the only thing you have not covered is timing- you need compression, spark, correct air/fuel mixture reaching the combustion area and correct timing of the spark.
That would be my first check- confirm the key is still intact on the internal taper of the flywheel and the keyway cut in the crank stub is undamaged.

Way to kick a dog while he's down hedger. magneto is new and keyway is undamaged.

 

[Bob Hedgecutter]

Wasnt kicking anyone- was the first logical place to be looking.
So you call a flywheel a magneto- you have replaced that as well?
Have heard of 440e's having coil and flywheel issues around lack of supposed magnetism and then doing the same with new, replaced with the old and they went back to working!

I assume it is the correct spark plug and with the repeated attempts to start the plug is getting wet?
Purge valve lines hooked up correctly- so it purges air from carb- not pulling from the tank return?
All the wiring went back in correct position after rebuilds- including the ground to cylinder?