Ariens Tecumseh won't fire

hanyoukimura

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So this is a new one for me. I've got an Ariens mower with a Tecumseh 5hp flathead. It's got compression, its got spark. I rebuilt the carburetor. Yet it doesn't so much as cough over, even with a shot of starting fluid or carburetor cleaner, in the carburetor or in the combustion chamber itself. I decided to check the flywheel key to see if it was sheered, throwing the timing off. It doesn't kickback at all, it doesn't do anything. The notch in the flywheel isn't quite lined up with the notch in the crankshaft. Would that be enough to be considered sheered throw off the timing? If not, what else could cause a no fire issue? Here is the mower (I forgot to get the model number)

IMG_20130522_173733_zps46dc1f9d.jpg


IMG_20130522_173718_zps90642528.jpg
 

Rivets

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Can't really tell with that style of key, but I think it looks good. Torque the starter cup and nut back on and set the armature air gap at .010. If it has spark, but won't even cough with a short of carb cleaner, I suspect the the coil is too weak to create a spark under compression.
 

hanyoukimura

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Can't really tell with that style of key, but I think it looks good. Torque the starter cup and nut back on and set the armature air gap at .010. If it has spark, but won't even cough with a short of carb cleaner, I suspect the the coil is too weak to create a spark under compression.

Yep, turns out the problem was the coil. Swapped it out and it fired right up! Thanks!
 

DaveTN

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Along that same line of trouble, I've also seen spark plugs getting some reddish-orange fire outside the engine, but put it in the engine and it won't get spark. It can fool you and make you think you're getting fire in the engine when in fact you're not. Needs good blue-white fire!
 

hanyoukimura

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Along that same line of trouble, I've also seen spark plugs getting some reddish-orange fire outside the engine, but put it in the engine and it won't get spark. It can fool you and make you think you're getting fire in the engine when in fact you're not. Needs good blue-white fire!

What threw me off was that I had checked for spark before posting this and it was blue-white. Works great now.
 
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