Hi, I was wondering the same because I don't know if both the cylinders fire every 180* which would be both in 360* or one revolution. I will be watching the replys as I want to add one to my X300.

Glenn

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Interesting detail brought up there about the firing frequency. Consider a single cylinder 4 stroke engine as an example (for multi cylinder engines, pick any one particular cylinder). If the ignition produces a spark for every revolution of the crankshaft......the spark plug is firing TWICE by the time the engine has gone through all 4 strokes. It fires at a few degrees Before Top Dead Center on the compression stroke (but the flame front doesn't really get going until a few degrees After Top Dead Center into the power stroke). The second spark occurs a few degrees Before Top Dead Center at the end of the exhaust stroke and is essentially "a wasted spark". This was always a characteristic of the standard 4 stroke engine ignition system and a spark was produced every 360 degrees (one half of the 4 stroke cycle), not every 180 degrees. Most late model automotive engines with distributorless ignition systems make a spark ONLY at the end of the compression stroke (a few degrees Before Top Dead Center). This ignition system gives a spark every 720 degrees of crank rotation (every other complete revolution of the crank)with no "wasted spark" on the exhaust stroke. I think this is what Tiny Tach refers to as a "true 4 stroke" engine (but as far as I know, I have never seen or heard that term anywhere prior).