Needles are in pairs ?

[Andrew Shadow]

On an aside but related, what possible reason is there for having different needle tapers (Jet Staggering) between left carbs versus right carbs ? Assuming its to affect mixture at mid throttle then what could be the difference between left and right side of the engine that would necessitate this

Good question for which I don't really have a quality answer.
Thinking out load, the only suggestion that I can offer is that they do this to try and squeeze the most performance out of the engine as possible by manipulating the fuel delivery to meet both the environmental conditions and emissions standards of each market area. Manufacturers generally try to keep the engine from running leaner than needed, in an attempt to get as much performance out of it as they can, while still meeting the emissions standards. Possibly four needles/jets of the same size is slightly to rich, while four of the next smaller size would be to lean. Maybe two of one size and two of another size, in the right combination, hits the sweet spot where they are at the maximum performance that they can achieve while still meeting the emissions standards.

On a water cooled engine, it probably doesn't matter much which cylinders pairs have which needle/jet combination as far as temperature goes.
As far as whether two cylinders on the same bank have the same combination or not probably doesn't matter either as the emission standards are not enforced on a per cylinder basis, but rather for the engine as a whole.

If ever you figure it all out, do let us know.

 

[aSTerix]

It will be curious to see what they respond. If they state that it is indeed a FWD/AFT split, as opposed to the LH/RH split that I have illustrated above, I hope that their answer also contains an explanation of how that marries with the existing directional indicators already contained in their diagram.

I did ask for this also but I suspect it will get overlooked in the interest of them clearing the query off their tracking system

 

[aSTerix]

Unfortunately, your question will probably be addressed by a dealer support representative whose job it is to field questions from dealers

Yes I suspect this also, I am using several different ways of asking Honda in several countries, wonder if they will work out where its coming from !

On the plus side, this is a sufficiently important technical query that it will warrant an official technical response and Honda don't like to be sued over technical inaccuracies