Forum

[Creaky45]

I am suspecting an intermittent fault with the coil on my 2006 Bullet as it appears to miss at high revs under load just like a faulty spark plug type miss. I have replaced the points, condenser (I call them capacitors) lead and cap (non-resistive) and spark plug. The timing is spot on. To eliminate carby problems I have swapped complete carbys with my mates Mikcarb which runs perfectly on his exactly similar bike. So I bought a brand new 12 volt car coil which was cheap as someone said this could be done. Alas, it started and idled perfectly but ran erratically at any speed. Took the points cover off and observed the points sparking a lot and not only on the contact area but round the sides also. I put the old coil back and no more sparking at the points and the bike ran well. But I will still have the high speed miss. Now I know the resistance of the car coil is a lot less than the RE coil and draws at least twice the current. I know they use ballast resistors in cars but that is only to give them 12 volts while cranking, then 8 volts when running. Maybe I should use a ballast resistor and drop the current. Have not tried that yet. Has anyone had experience with different types of coils.

[Leon Novello]

I had a second-hand Honda once which had these symptoms. The seller had told me that it had a car coil. Mechanics could never fix the problem, until I bought a genuine Honda coil and all the problems went away.

[Revband]

Coils are coils, but, all coils are not born equal and you must use the correct type, points ignition and electronic ignition use different coils (some BB units excepted) also as you say some early car type use a ballast, try the correct coil.

[Mark M]

I hate to throw a spanner in the works but I had the same problem on a GT which I solved by replacing the battery. I had a similar problem on a Super Meteor too but at low revs and that was the rectifier. I mention that just to illustrate how components that don't seem to have any relationship to the problem should also be considered, but only after the most likely culprits have been eliminated! (Sorry, been watching too much SS:GB)

REgards, Mark

[Creaky45]

Mark, My battery is quite new, I have a good reg/rec and the alternator is charging fine. I guess I should order a new one to prove it one way or the other. But first I will try a resistor in series to make it appear the same resistance as the original. I will keep you posted. Thanks for your replies.

[Gwilly]

Dont like the description of sparks around the points area, be worth checking all insulating washers and wire integrity..

Correct coil would narrow the scope of possible problems..

Assuming regulator and wiring connections has been checked and found satisfactory then one test would be to temporarily connect a lead direct from battery plus to coil, thus bypassing ignition switch and kill switch circuitry.

Not unknown for ignition switches to play up on 10 year old bikes..

Obviously you'll have to stall the bike or use decompressor to stop the engine but just as a means to eliminate that area of components and loom..