Topic: Cylinders going on and off

[Anghil]

I've had this problem with my bike for a few months now, but only recently has become a serious problem, possibly from what I was doing, or lack thereof.

Once in a while, while riding, two of my cylinders would shut of and I'd lose most of my bikes power. I could still ride, but it was obviously much weaker. This would usually only last for a few seconds to a minute and then the cylinders would fire back up. Recently however the nike's been stuck in its 2 cylinder mode and I can't figure out the problem. Replaced the plugs, swapped out the battery and turned it on. It lasted for about a minute before it killed off 2 of the cylinders. My mechanic neighbor recommends swapping out the ignition coils.

Anyone have an idea as to the problem and a remedy? Did I worsen the problem by not addressing the issue immediately? Thanks!

[Airborne 82nd]

First figure out the two you are losing. if they are on the same coil 1-4 or 2-3 this will help solve the problem. Check if the two have fire. Are two pipes cold?

[70CB750]

Yes, swapping coils is the best start, if the issue swaps too, you found it.  Say 1,4 are cold, you change point signal and spark plugs cables and now 2,3 not firing - it´s the coil.

[brewsky]

Watch the points as the bike is running. If one set is obviously sparking more than the other, it probably is a condenser.

[Anghil]

Already know it's 2 and 3 not firing. Fuel is reaching the plugs, there is spark when i test it, but don't know why it's not igniting. -

[BobbyR]

A few things to look into:

Do you have a Dyna, they fail that way.
Did you unscrew the plug caps and clip a tiny piece of the end and screw them back in.
Check the wire that goes from the points cover to the coils. They can get chafed.
Run the bike in the dark and look for arcing somewhere.
Since this is an ignition problem, a point by point check find the problem.   

[Anghil]

I do have dynatek ignition system. Clipped off the little tabs on the plugs. I'll check the wire. Haven't seen any arcing. Thanks for the tip. I'll update after this run through! -

[Brantley]

Sounds like classic Dyna. Got a points plate you can swap in?