Intermittent ignition miss

IA Roy · Aug 12, 2016

I have an old 16 hp single cylinder cast iron Briggs and Stratton. It has an intermittent ignition miss after replacing points, condenser and spark plug. After 10 to 15 minutes it can stop. I converted this unit to battery ignition with a mid 80's ford ignition coil and a ballast resistor about 15 years ago and it worked fine. Is there a way to determine what is causing the miss? I am thinking it is probably a bad new condenser or the coil? I confirmed the miss with an inductive timing light. I have another similar coil, or I can get another condenser, either used or new. Posted on Tractor Talk also. Thanks, Roy

MNGB · Aug 12, 2016

My guess is its the points those engine are very fussy with the points, they are normally open and the plunger drops into a small indention in the cam and if the spring tension on the points isn't strong it can not close well causing a miss or ot could be that the new points have a light film on them try spraying carb cleaner on the points first, a bad condenser generally show up at high R's engine may idle fine but misses and even backfire at high R's, coil will generally show up after it warms up say after a 1/2 hr or more.
GB in MN

T.R.K. · Aug 12, 2016

The last one that ran with a miss like that turned out to be the coil.

You can file the points if they are questionable. If there is metal transfer from one of the points to the other, the condenser and the coil are not matched close enough. (I read that in an old manual once. Don't ask me to tell you how to find the correct condenser for it. I don't know how.)

Try a known-good coil and then a condenser on it.

Intermittent ignition miss

IA Roy

Well-known Member

MNGB

Well-known Member

T.R.K.

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