Primary chain and rubbers

[Sesman]

Quick question all. To replace the primary drive rubbers do I just remove the shaft snap ring or do I need to dismantle the starter gear (three jis screws).

Thanks in advance.

[Bryanj]

Yes

[Sesman]

Thanks Bryanj…just the snap ring?

[Sesman]

Bugger me. It’s off and the rubbers appear to be just fine…all soft and yielding. Tomorrow I’ll compare with the items I ordered from DS.

[deltarider]

Some oils are nicer to rubber parts than others, at least in my experience.

[Sesman]

Which ones?

[Sesman]

I should add that this machine has been stood idle for 40 plus years having covered 19k miles. I’ll replace them now, but a good lesson in checking prior to order.

[Bryanj]

Its unusual to see them ok after that time

[deltarider]

Which ones?

I have good results with Castrol High Mileage 15W-40.

[Sesman]

Hi, Bryanj. So I understand, but they seem fine. I’ll compare with the new replacements I’ve ordered, today.

Incidentally all the evidence suggests this motor has never been apart. Wonder if Mr Honda changed the rubber formula during production.

[Sesman]

Thanks delta rider. Do hope I haven’t triggered an oil debate  .

[Bryanj]

I doubt that those rubbers changed, heat cycles would affect more than age but age does it as well

[deltarider]

I can only share my personal findings. In the past I've used various oils. The one I disliked most, was the Mobil 1, in those days regarded as the very best. On the top of the Pyrenees at the French Spanish border, I detected leaks at the oil pump seals. Some months later a little smoke on decelaration indicated leaking valve stem seals. They have been replaced in an top end overhaul. Ever since I've used that Castrol High Mileage, I have had no further oil leaks (apart from the head). On the contrary: the notorious shifter seal which leaked a lot before, seems to have cured it self. Although Castrol seems to have abandoned the name 'High Mileage', some oil suppliers in their sites stress, it's still the same High Mileage oil. You may also want to read this: http://forums.sohc4.net/index.php/topic,187317.msg2171984.html#msg2171984
Note that these are my personal findings on my CB500. I cannot comment on the condition of the rubber parts in the engine: I've never set eyes on them.

[Trigger]

If the primary unit came apart very easy then the rubbers are worn. You will find this out when you try to reassemble the unit and find it tight. A smear of red rubber grease makes it easier to get it back together 

[Sesman]

Hi, Trigger. I very much appreciate your input. The drive needed a sharp downward rap Ona piece of softwood, then leverage. It certainly didn’t fall apart and needed persuasion. I’ve just received new replacements and will report shortly. Thanks again.