The International CBX Owners Association

When people hear or see you have a CBX there always is a comment.

I heard one the other day about the inner cylinders getting hotter than the rest so the "trick" set up is to Jet these a little richer.

That's the question?

I think this would be interesting "But" think un-even power to the crank would be worse than "if inner cyl. getting hot".

Besides, I have not seen anything about this on the Tech page.

Though I would ask from those who know.

Thanks,

Later,

Ed

Hello Ed:



I would agree with you that this is a complex matter not having a simple solution as setting the mixture richer. The reason the outer cylinders run cooler is, of course, the larger surface exposed to the air stream dissipating heat. The fact that we have heat to be dissipated is a result of the inefficiency of the internal combustion process. As already said somewhere else, a gasoline engine converts only about 28-30% of the energy induced in the form of combustable hydrocarbon molecules into useable energy. The other 70% are heat out of the exhaust and through the engine enclosure. If we give one cylinder more energy in form of a richer setting, the losses in form of heat remain the same, just the exhaust gas carries a higher amount of unburned fuel and less hot air. A lean setting has the opposite characteristics: Excess air that is not being burned, goes out the exhaust and turns it blue. This issue needs to be addressed when an engine is being designed and I would think Honda's engineers did this way back in the late 70s. Playing with the mixture to obtain a more even temperature balance would not be an option for me. Achieving optimum efficieny is definitely a goal and warrants fiddling with the carbs as Honda may have had other things in mind with the original setting.