W4 not starting

Terry MN · Jan 25, 2010

My W4 is turning over but not starting. I changed the plugs last week and then it started. Now today it is not starting again. I know it is getting gas because I see it draining from the carb if I turn the choke on. I removed the spark plugs and dried them out.

I'm wondering if it is the magneto that is causing the problems? Once it starts it runs very good, just getting it to start is the problem. Any ideas on what the problem is and how I should fix it?

Thanks.

Janicholson · Jan 25, 2010

One possibility is that the magneto impulse coupling is not snapping at cranking speeds. There is a system in the Mag that holds the magnet with a latch and spring. As the mag turns at low (cranking speed) the latch momentarily holds the guts of the mag, then at TDC of the cylinger, it releases. This windup increases the speed of the magnet in the mag, allowing it to make good spark with near no engine speed (works with hand cranking).
If the mag is clearly making this snapping noise when hand cranked, or listened to at the mag when cranking with the starter, it is something else.
Pull starting it (no faster than 4 mph in 4th gear) will start it even if the impulse is not operating. This is because the running engine does not use the impulse system as it has enough speed to generate spark. JimN

El Toro · Jan 26, 2010

Pull off one of the plug wires and hold it away from the sparkplug while a helper makes an attempt to start the the engine. If its not a hot blue spark your mag is the problem. Do as Jim suggested in checking the impulse couping, but you may have a weak coil or weak magnets. Hal

mkirsch · Jan 26, 2010

Terry MN, quick survey question here...

Did anyone ever show you how to check for spark on a chainsaw, lawn mower, rototiller, go-cart or other small engine?

Just wondering, because I thought that was pretty much a universal thing, yet so few people know how to do it.

To check for spark, you pull a spark plug and stuff it back in the wire. Lay the plug's business end against the engine block, and crank the engine over.

rustred · Jan 26, 2010

yep, like when i was 9 or 10 yrs.old and used to play around with those little iron horse engines. tear them apart and put them together and make em run.just unbeleivable at some of the things grown ups dont know.

Terry MN · Jan 26, 2010

Since I am 14 years old I still have time to learn then right

rustred · Jan 26, 2010

you bet , you have a whole life time to learn things, good luck.

Anonymous-0 · Jan 26, 2010

You know its smart sarcastic fukers like you that will never teach anything. You probably a greedy good for nothing welfare case. There is a very good possibility of you being the type that can do everything better and faster than the next guy that everyone hates.
If i were close to you checking for spark i would stick the plug wire up your rear end where the sun doesn't shine then crank it over, cause that's all your good for.

On another note Terry you might want to try starting fluid, but it does sound like a mag problem.

grg1938 · Jan 26, 2010

Why such language on here. We are here to learn from others not put them down! Not everyone had the experience others had.

W4 not starting

Terry MN

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Janicholson

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El Toro

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mkirsch

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rustred

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Terry MN

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rustred

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Anonymous-0

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grg1938

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