Mercury 150hp V6 2-Stroke - Using timing light while on Idle

[rtrevino]

Hey Guys, I need your expertise on the following. Yesterday I attached my timing light to my engine trying to search for a coil that might not be firing. I was going through the coils one by one until out of curiosity I decided to point the timing light at the Dial Indicator Window. I discovered that while "on Idle" on plugs 1, 3 and 5 the indicator will show "0" (Zero). But when switch to the other bank (2, 4 and 6) nothing will show. I can barely make the .464 mark to the right of the window. My questions is ... Should both banks show the same reading? Am I even testing anything here?

Any comment is highly appreciated.

 

[Texasmark]

Probably the light lights when the timing mark band is on the other side of the engine. You'd have to look at a crank angle position guide to know for sure. The light lights when that plug fires and not all fire at around 0 - 25 degrees on the flywheel beins there are 360 degrees from which to choose and they fire around the circle for engine smoothness.

 

[Chris1956]

Remember that motor will fire 6 times in 360* of revolution. If you had 360* of timing marks, you would see it fire at 0*, 60*,120* etc.

Since the firing of all cylinders is keyed off #1 cylinder, if that one is correct, the rest should be correct too. So if you observed the timing light firing on all 6 spark plug wires, you should be OK, as long as #1 plug fires on time.

 

[rtrevino]

thanks you both.

 

[Texasmark]

Happy boating

 

[enginepower]

Are you saying that putting the timing light on 3 and 5 will light up on the flywheel in the "0" position of flywheel as well? If so, you have a firing problem because they should light the flywheel at another point 60 degrees away like Chris was explaining. Best way to do it is to remove all plugs and use screwdriver or whatever to find when piston is on very top and mark it's number on the flywheel at the timing mark "0" position. All of your numbers will be 60 degrees apart. Then, when you use timing light, you should only see the number that you have timing light on at the "0" position.

Edit: Oh, and if you see any number in that position other than the number cylinder you have it on, you have an ignition problem. (bad trigger, cracked magnet or whatever) Put a video to help. https://www.youtube.com/watch?v=D-hBeGdE6oE