Topic: Ignition coil....condenser?

[hsas.69]

Im pretty sure i have an ignition coil bad wanted to ask around as well. 78 CB550K stock ignition, stock carbs rejetted for foam filter and exhaust. Runs great until things get up to temp, then starts to develop a light throttle miss. If i grab a handfull it pulls fine. The miss gradually gets worse until two cylinders are just dead. All within a short warm up and probably five or six miles of cruising.

Tried a new set of plugs i had already just in case. Anyone think of anything other than a coil that im not thinking of.

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[johans]

condenses fail when they warm up , ask me how i know. Go for original points,plate and condensers . It will save you a lot of grief..

[PeWe]

Add Hondaman ignition module too and less need for condensers.
My last CB750 K2 build had a behavior where  I suspected the very old condensers so I disconnected them. It runs fine without them.
My K6 got some occasional misfires at around 8000-9000 rpm without condensers.

[hsas.69]

I thought maybe a condenser. For the cost wouldnt hurt to try some before doin coils.

I might try that PeWe unhook them and see.

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[TwoTired]

The coils.  Literally two coils of insulated copper wire in physical proximity.  Rather Hard to kill without physical abuse.

Condenser: two layers of conductive foil separated by an insulating material. 

Condensers far more likely to fail with time (dry out) and use (arcing between plates due to insulating material breakdown).

Cheers,

[jgger]

I would say it could be either one, condenser is cheaper to throw at it than a coil. Switch the condensers and see if the issue follows. If it does then condenser, if  it doesn't then most likely coil.

I had one go bad from moisture, it would run like a raped ape until it got warm then it would quit. Cool dod and back to running great until it got warm again. It wasn't a SOHC Honda, but the principal is the same.

Good luck.

[Jore]

I used ford pinto condensers, iirc they where for a '74 model the 2.4L one

[PeWe]

I thought maybe a condenser. For the cost wouldnt hurt to try some before doin coils.

I might try that PeWe unhook them and see.

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You must have Hondaman ignition for that. Stock ignition must have condensers.

[Spanner 1]

In the 10 years I've been on this Forum I can't even remember a case of a bad coil ! They just don't fail even after 50 years like my K1 750. Condensers and heat, absolutely . The bummer is any condensers your gonna' buy in 2019 are going to be ( very ) old stock and already dried up IMO . So, the ultimate ignition for our old bikes is Hondamans 'ignition booster' in tandem with the stock points. Suits the charging system ( very important ) and you can do away with the condensers . If you make that mod be sure the points plate gasket is solid as any moisture at the points is a no-no due to the much reduced current across the points which can be interrupted by condensation in there. Good luck !