I have a briggs Vanguard 16hp V-Twin with no spark. Had trouble with it a couple months back (no fuel and no Spark on one side). This engine is mounted in a van and used for turning carpet cleaning equipment Gets a lot of hours year round. I figured I'd do some work on it while I had it out, here is what all got done: Replaced head gaskets, rebuilt and cleaned carb, new solenoid, new plugs, new fuel filter, adjusted valves (set to .004) and replaced the magneto on side with no spark.

Been working and running fine for a couple months until today. Started right up and ran for about 10 minutes and shut down. Would crank but will not fire. Plugs looked pretty dirty for only a couple months old so replaced them again and checked for spark. Spark was there with new plugs but seemed intermittent/week. Put them back in and tried to start it, no fire. After checking spark again, I now have none. Like I said, one magneto is new and it is not likely both would go at the same time. Anything else I should check? The only kill switch is connected to a float in the dirty water tank, tank gets full, shuts down the engine as not to over flow the tank, seems to be functioning fine.

Unhook the ground wire where it hooks to the engine and check for fire, depending on the model # of the engine it could have an inline diode going to the coils. If you could give the model and type I could check and see.

Not sure why I didn't give the #'s to start with. Model= 305447 Type= 0079-E1 By ground wire, you mean the main coming from the battery? That's the only ground I see going to the engine.

Imean the little kill wire going to the coils on the engine ,should hook on the side to what looks like a little square plastic nut.

Yes sir, unhooking that ground did in fact give me spark back. It will even start and run but sounds like it has no power at all.

Ok, take that back, it was only running rough because I did not put the spark plug wire back on one side. HAHA, with both plugs firing it runs just fine. The ground wire (x2) I removed as you asked, looks like one traces back to the ignition switch (key) and the other goes to an oil/water pressure bypass switch. On this unit the switch is used to start the engine. Hold the switch over while starting to bypass oil and water pressure until it builds up.

As it sits right now, it seems as if I could go clean some carpets and make a few bucks, but obviously there is still something wrong.

This may be a stupid question but... What are the coils anyway. I pretty much have taken this thing apart three times and put it back together again and still do not know what or where the coils are.

Its showing that it could have diodes inline going to the coils.need to remove engine blower housing and check it out.
Part # 578A or 578E . Luck