4hp briggs gap for armature?

[cephas]

Am working on a 4hp briggs lawn mower engine, approximately 5 years old or so. Does anyone know the proper gap spec for the armature from the flywheel? This unit has had problems surging and the culprit, I think, was a crack in the plastic intake tube from the carburetor. I've sprayed the carb clean, checked gas cap and cleaned the muffler. Any advice appreciated. Thanks and have a good one!

 

[yeehaw1960]

I eyeball it. You can take a business card and place it between the coil and the flywheel. Tighten the bolts and pull the card. That's plenty close enough for government work. If the surging is still going on, these tank-mounted carbs are notorious for having bad diaphrams. That's normally the cause of surging. It's an easy replacement and the part can be had for 2 - 6 bucks depending on where you get it. Remember...the thin diaphram goes agains the tank and the gasket goes against the carb. Have fun.

 

[UNC038]

Quote:

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I eyeball it. You can take a business card and place it between the coil and the flywheel. Tighten the bolts and pull the card. That's plenty close enough for government work.

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I've used the back of a match book as a guide. Close enough for me.

 

[yeehaw1960]

I used to keep a piece of aluminum roof flashing big enough to go between both legs of the coil and the flywheel to use to get a "pretty close" gap. Now that I think of it, I might cut out another piece....where did grandpa's piece of aluminum run off to now!?!...

 

[Bill Kapaun]

http://nevadawalrus.com/spec-index.html

 

[Slick 55]

.010" to .012"