Marvelicious
Naturally Aggravated
I wasn't thinking about dual coils - yes with a dual coil, there can't be a difference.
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Timing Difference Between Plug Wires (the next problem)
- Thread starter Rlauchard
- Start date
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- Tags
- cylinder engine spark plug timing
Rlauchard
XS650 Addict
Like I said, there is a difference.
Like Pete said, the difference is probably me.
I'm moving on...but I'm sure that this will eat at me.
Marvelicious
Naturally Aggravated
Well, my point was to agree with Pete - it has to be measurement, because it is a complete circuit that goes through both plugs. One won't fire without the other.
In a twin there's a cylinder that needs firing every crank revolution. The cam only spins at half the crank speed. If you put a single trigger on the cam making one spark per cam revolution, that would be only one spark per two crank revolutions, not enough. You need a second trigger in there positioned 180 degrees from the first, in the pamco I assume that's gotta be a second triggering magnet drilled 180 degrees around the disk from the first. Nothing about it being a single coil system has any effect on how accurately drilled those trigger magnets are. If the drilling tolerance was a little off the two sides could never fire at the exact same point in their strokes.
Pete's offered some ways to determine if it's just a measurement artifact, so it could well be that, but to say it's impossible for a cam triggered ignition to be out of balance doesn't seem right.
Pete's offered some ways to determine if it's just a measurement artifact, so it could well be that, but to say it's impossible for a cam triggered ignition to be out of balance doesn't seem right.
pamcopete
Ride.Enjoy.Life is Simple
Greasy,
If the magnets were not exactly 180 degrees apart or if they had a different magnetic strength, then you would see two strobe marks on both sides. Each trigger magnet fires the same coil 180 degrees apart, so you always see both strobes on both plug wires. If they were, say, 175 degrees apart, you would first see one and then 175 X 2 = 350 degrees later you would see the other. Because of the persistence of the eye ball, they appear to happening at the same time. In other words, the two strobes would appear to be 10 degrees apart on both plug wires. This is a possibility, but it is not what Rlauchard has observed.
If the timing chain were badly stretched or needing adjustment, then even if the trigger magnets were exactly 180 degrees apart, it would still be possible for them to fire at some effective separation other than 180 degrees, but the result would be the same. Two strobes would appear on both wires.
If the magnets were not exactly 180 degrees apart or if they had a different magnetic strength, then you would see two strobe marks on both sides. Each trigger magnet fires the same coil 180 degrees apart, so you always see both strobes on both plug wires. If they were, say, 175 degrees apart, you would first see one and then 175 X 2 = 350 degrees later you would see the other. Because of the persistence of the eye ball, they appear to happening at the same time. In other words, the two strobes would appear to be 10 degrees apart on both plug wires. This is a possibility, but it is not what Rlauchard has observed.
If the timing chain were badly stretched or needing adjustment, then even if the trigger magnets were exactly 180 degrees apart, it would still be possible for them to fire at some effective separation other than 180 degrees, but the result would be the same. Two strobes would appear on both wires.
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Rlauchard
XS650 Addict
My understanding is that the BS34's needles are not adjustable. I'm going to move on to other things right now. When the bike is warm, it's doing awesome...so I don't want to be making changes to engine right now, until the weather is a bit more serviceable. Moving on to wiring, body components and fab work and will address the jetting when I get the engine in final stages.
He didn't, he said points but ment Pamco. He swapped most likely because the TCI broke down.
When the TCI quits you either try to find a good used one or swap to a different iginition.
Leo
When the TCI quits you either try to find a good used one or swap to a different iginition.
Leo
