Arcing Points

[Husbyb86]

Hi, I've been lurking on this forum for quite a while now. I've learned a lot here but now I've got a question of my own.

I picked up a '66 Cl77 a couple years ago (all original, including paint!). It's always been pretty reliable when warmed up but starting has always been kind of a problem. It tends to start on one cylinder (randomly one or the other) with lots of popping until eventually the second gradually kicks in. Anyway, I've narrowed it down to the condenser, as everything else has been replaced and checked over and over again (coils, points, timing, float height, etc). I've used the "tuning recipe" on here several times, and still end up with the problems at start up.

I've got a new condenser on the way (OEM style) but would like to know why my points seem to arc so badly at startup but then seem to calm down after a minute or two, followed by less popping and both cylinders firing. Is my condenser just slow to "warm up"? Thanks!

[husabob]

It has been my experience that condensers break down as they warm up. Perhaps your coils are at fault.

[LOUD MOUSE]

Or the points are dirty and/or pitted. ......lm

It has been my experience that condensers break down as they warm up. Perhaps your coils are at fault.

[Husbyb86]

I put new points in a couple days ago and that didn't seem to lessen the arcing. Also, I've tried swapping coils with another Cl77 and unless those were bad too, that also didn't seem to solve it.

I often hear these bikes are "cold blooded". Do others experience a rough startup w/popping?

I'm hoping this new condenser will solve the problem.

[husabob]

I don't know about arcing points, but the centrifugal advance can cause differential timing issues between the two cylinders if it is not operating correctly. This could cause the "popping". I have not experienced this with my CL77, but did on my /2 BMW.

[Husbyb86]

I'm not too familiar with the advance mechanisms of the Cl77 but have noticed the rotor advances when throttle is applied while using a timing light. Where is the advance plate located? I can't seem to find anything on the microfiche. Is it behind the points plate? I will take a peek this morning. Also, if/when I find it, what should I check for? Worn springs? Should there be any free play at all?

Also, the bike has about 10,000 original miles. Should I expect a worn advance mechanism?

[jensey]

The advance mechanism is located inside the cam sprocket, cam sprocket is located inside the engine-head, check the parts manual , for example at CMSnl.

I don't know about arcing points, but the centrifugal advance can cause differential timing issues between the two cylinders if it is not operating correctly. This could cause the "popping". I have not experienced this with my CL77, but did on my /2 BMW

Not the case with the CB/CL engine, as one advance mechanism works for both points the same time, every revolution, thus not the case.

The springs in the advance mechanisms are prone to weaken over the years, not really depending on mileage. The effects are different then your description, thus also not likely the case.

Did you check your spark plugs and spark plug caps ? Cables ? electrical contacts ?

Jensen