# Briggs & Stratton no spark



## DIYinMI (Jun 27, 2012)

Read through a similar post from a couple of years ago, but it didn't answer my problem.

4.5 HP Briggs & Stratton lawnmower (Sears), no spark.

Original problem was surging, rough running & fouling the spark plug. Had this happen a few years ago and a new gasket in Carb fixed the probelm.

So I installed new gasket in carb. Did not touch coil (armature). No start even with starting fluid. Determined no spark. I didn't hold spark plug lead, but instead removed plug and grounded it. No visible spark.

I ordered new armature and installed it. It IS right side up. Although at this point I'm about to try it upside down... On the post I read about this (couple of years ago) that turned out to be his problem.

I tried both hand turning the flywheel (without the plug installed it will spin pretty fast) and reinstalling the recoil pull cord and yanking the heck out of it. No spark.

I tried it both with and without the kill wire attached.

Not sure what gap is required. Old armature seemed to be about .013. I tried that and larger and even tried it with it touching slightly (by hand and not by pull cord). How sensitive is the gap??

HISTORY
Now the gasket change I did years ago worked nicely for a season or two and then it quit running completely. No spark. 

I did ALL the same things then, as I did this time. New armature, still no spark. Ended up taking the whole thing to Sears for repair. They installed new armature and new carb and charged me within pennies of what a new unit would cost. I expected that and I am not complaining, but I'd rather not do that again...

Now two years later and here I am again. This can't be THAT hard to fix...

At $30+ bucks an armature, I'm not going to order another one. What multi meter tests can I perform on these armatures?


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## Basementgeek (Feb 7, 2005)

Hi and welcome to TSF

Please give us the model number off the enginge.

Just how old is this mower?

BG


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