The International CBX Owners Association

Part number for primary shaft seems to be same for all models. I am aware of other parts changed regarding primary shaft, starter clutch etc. in later models.
Could someone confirm is the primary shaft itself same in all models?

-piit-

Yes, the bare shaft is the same for all years.

Dave

Thanks Dave. Let´s continue, I saw one shaft picture in ebay and the shaft has somekind of plug in altenator end? Should the shaft be "plugged"?
Shaft in my engine is without the "plug". Would this cause "strange" sound that I have located to come from primary chain area? If I have understand right this is linked to the
primary chain tensioner oil pressure as well.

I am running with Kawa alt, so the primary shaft is totally open.

-piit-

That aluminum plug is a metering orifice for sending oil to the alternator clutches. Two concerns I have in running the bike with the plug missing: Oil is just dumping into the alternator clutches, and more importantly, possible loss of pressure to other areas of the bottom end due to that large 'dump' into the alternator.

Dave

Thanks again. Wondering how this plug can be missed I know the plug has never been there when I have owned this bike.
I will machine the aluminium plug. As running with Kawa alt I will not need orifice, any ideas?

-piit-

The plug is not tight in some bikes and can fall out when the alternator is removed. Usually ends up in the oil pan and set aside as a curiosity since not many know where it goes. The plug is very slightly tapered if you are making one.

Dave

Thanks Dave. Yes, I am going to do plug. I have been told that the orifice is 1mm in the plug.
Just wondering do I need this orifice i.e. can I put plank plug as I am running with Kawa altenator.
However, I am planning to glue this plug.
-piit-

The plug can't fall out with the alternator in place.

Dave

Right, I will check in further. I will report the results here. I will do aluminium plug with 1mm orifice.
-piit-

Need to correct what I said earlier. I removed the clutch cover and there was not aluminium plug in the ignitor end of primary shaft, it was ignitor shaft that looks like a aluminium plug with orifice when lurking with flashflighter from altenator side of the primary shaft.
I made aluminium plug with 1mm orifice tapped it in and ´voila´. The strange sound is almost gone, sounds pretty cool even with 100 celcius full synthetic 15/50W MC oil (this is the oil that I know my CBX does not like, but I had it in shelf).

I am wondering how many shafts there are out without this aluminum plug

Attached the picture of home made aluminium plug.
-piit-

There you go - nice work!

Dave

Okay Dave, I have to ask why the evolution of the primary shafts?

Would be wise to update a 79 engine with the later primary shaft?

Mike

Mike:

It was Honda's attempt to quiet the resonance rattling of the clutch. They identified not only the clutch basket as the culprit, but the rather loose fit the primary drive chain sprocket had on it's shaft. They re-designed the sprocket with a split nose and a locknut to tighten it firmly to the shaft. If you had an upgraded one there to install, maybe worth it, but I wouldn't tear apart an engine just to do it. Most noise can be quieted by fixing the clutch basket or replacing with a $500 late model one.

Dave

Thanks again to support me with my plug problem

cbx_daniel from cbxworld forum posted an excellent picture of the shafts:

Thanks Dave,

I now have another nugget of information .

Mike