Intermittent Ignition woes

[duantro]

Yes, the bike was running good prior to dyna Install. When key is switched off, it is definitely delivering a spark and igniting unturned mixture thru the exhaust, if the valve is open. I've verified spark with a timing light also.
I will check instrument oil and alternator lights in a few minutes.
Edit: yes, I am getting oil and alternator lights. My oil light housing is a hair loose. Do you guys crimp the housing or wrap wire or something around the bulb holder to keep it in place?

[Dan in IL]

Having a cylinder fire when turning off the key is normal with an electronic ignition on these bikes, so don't worry about that, it has nothing to do with your problem. It sounds like you have a real gremlin to track down!

[hal]

Have you tried push-starting the bike? Would rule out the batteri..

[duantro]

Have you tried push-starting the bike? Would rule out the batteri..

Good idea! I will try this ASAP

[jagarra]

Seems like your ground path from the points area is not working right or has a bad connection. Since the coils fire when the points close providing a ground path and it was good beofre the installation of the Dyna unit. It was intemintant after with the re-installation of the points, I would look in that area.

Another method to eliminate the coils and battery would be to supply 12v to the coils from another source while trying to start with the on board battery.

[Ken in Oklahoma]

Seems like your ground path from the points area is not working right or has a bad connection. Since the coils fire when the points close providing a ground path and it was good beofre the installation of the Dyna unit. It was intemintant after with the re-installation of the points, I would look in that area.

Another method to eliminate the coils and battery would be to supply 12v to the coils from another source while trying to start with the on board battery.

I think you meant to say that the coils fire when the points open.

While the points are closed the coils "saturate" because of the current flow. When the points open that current flow is interrupted and the voltage builds up in both the primary and secondary coil windings. When the voltage rises high enough in the secondary an arc sparks across the plug electrodes, igniting the fuel air mix.

Sorry about being pedantic, but I thought it important to note.

Ken

[Major Softie]

I think you meant to say that the coils fire when the points open.

Ken

I don't know if he "meant to," but he should have meant to.

[jagarra]

OK, I may have got the sequence explained ass backwards, but the theory of something amiss in the point breaker area is still valid. It worked before he installed the Dyna for the first time, it didn't after that point.

Sometimes doing something you think is an innocent change will cause a problem, like changing a buggered screw with one just a hair longer, and that extra length touches something.

I guess one has to work on the theory that when you change something and a new problem comes up you did something inadvertantly to cause the change.

gg

[Duane Ausherman]

I have seen our road racer have a flat spot in the rpm range. At the track we had to trace it down to a throttle cable vibrating against a coil terminal and shorting out the ignition temporarily and then running just fine for awhile.

There is another place where ignition can short out at a certain rpm.

While rare, there are quite a few oddities that can cause similar symptoms.

[Major Softie]

I guess one has to work on the theory that when you change something and a new problem comes up you did something inadvertantly to cause the change.

gg

Yes. Absolutely. Also: no.

Yes, when you change something and a new problem comes up, the first thing you should consider is that what you intentionally did somehow caused the problem. The second thing you should consider is that something you unintentionally did somehow caused the problem. However, you must also remember that the third thing you must consider is the possibility that the new problem popped up with absolutely no connection to anything that you did.

As clearly defined by Murphy, regardless of which of these considerations you choose as your first consideration, it will be the wrong one.