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Discussion Starter #1
I have my bike completely taken apart and I can't figure out if one cylinder fires, then the other fires almost immediately after.. that it like 45 degrees or whatever, or if one cylinder fires then 315 degrees or whatever after the other fires? I can't figure this out and the manual isn't very clear. I am trying to get the cams adjusted correctly and need to know this.
 

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The manual, either Clymer or Kawasaki, explains how to install the cams. Follow their instructions to the letter.
 

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Linkmeister Supreme
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The ignition pick-up coils, (or pulse coils I believe Ma Kaw calls them), get a signal on every revolution of the crankshaft from the magnet in the alternator rotor. So there is a waste spark in the exhaust stroke too.
 

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It's a 4 stroke.. Each jug once every 4 turns of the crank. Being a twin you you get one firing for each 2 turns.
 

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The plugs spark every time that the piston hits the top;however, you only get a power stroke every other time.
There I go thinking again. You are correct in that it will fire off on the exhaust stroke. My bad....
 

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Old Truck Junkie
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That is where the big back fire comes from when the battery is low. The fuel builds up and the spark is to weak to ignite on the power stroke, but it will ignite the feul on the exhaust stroke. So bang, out the exhaust valves.
 

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That is where the big back fire comes from when the battery is low. The fuel builds up and the spark is to weak to ignite on the power stroke, but it will ignite the feul on the exhaust stroke. So bang, out the exhaust valves.
That sort of makes sense, but how can the engine run if the spark does not ignite the air/fuel mixture on the power stroke? I'm assuming you mean it doesn't completely burn it, and ignites what little may be left in the combustion chamber on the exhaust stroke. That is very common on all engines, but more so on a V type engine, whether a v-twin or a V8. Kawasaki's air injection system makes the problem worse, by injecting air into the exhaust, causing whatever air/fuel mixture may be left on the exhaust stroke to backfire that much worse. However, my assumption has always been that the reason the Vulcan has 2 plugs per cylinder is to facilitate complete burning of the air/fuel mixture by igniting it in two different places. That's what dual plug heads are usually used for.
 

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That sort of makes sense, but how can the engine run if the spark does not ignite the air/fuel mixture on the power stroke? I'm assuming you mean it doesn't completely burn it, and ignites what little may be left in the combustion chamber on the exhaust stroke. That is very common on all engines, but more so on a V type engine, whether a v-twin or a V8. Kawasaki's air injection system makes the problem worse, by injecting air into the exhaust, causing whatever air/fuel mixture may be left on the exhaust stroke to backfire that much worse. However, my assumption has always been that the reason the Vulcan has 2 plugs per cylinder is to facilitate complete burning of the air/fuel mixture by igniting it in two different places. That's what dual plug heads are usually used for.
I mentioned a low battery. Therefore a weak spark under compresion. A build up of feul at a no compession state and the weak spark is able to ignite it.
 
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