CB500K2 four 1975 parts needed Rev counter drive cap Sorted

[martin_uk]

Continuing with my rebuild of basket case I bought and cant find the Tacho drive cap that the cable fits into on the cam cover.

If somone has one spare would be much appreciated if you could PM me.

Thanks

Martin

[Oddjob]

Rare and expensive as a rule when you can find one. DS still has 3 left in stock IIRC but it's bloody expensive for a small piece of alloy. https://www.davidsilverspares.co.uk/parts/by-part-number/partnumber_12451323000P

As yet it's one of the few parts not being made aftermarket, I was trying to get some made out of phosphor bronze as the alloy snaps far too easily. They would need CNC machining though and that's not always possible or cheap.

I do have a spare NOS one but I'm not sure I want to part with it, if the offer was right I suppose I would.

[Bryanj]

That DS one is a pattern part made by original company Kem(P on end of number) and it used to be dearer than that!

[Oddjob]

I thought that Bryan but it does say OEM, which is misleading.

Bloody expensive for a copy IMO.

[Bryanj]

Lot of different accurate machining in there, i wouldnt want to make one

[Oddjob]

A CNC machine should be able to do it, it's just getting all the figures right in the coding I'd imagine. Not that I can operate a CNC machine but that's the way I understand they work.

[Bryanj]

I did a small amount of cnc when i was a techician at Stroud college, took hours to work out program and if you got a number wrong you destroyed a tool

[Oddjob]

I've asked Scott (CR21) and he reckons a CNC would make them, however the cost is high for the initial outlay, it would depend on how much to make them, what to make them out of and what demand is like.

[TezzerTel]

I've got a spare if your stuck

[K2-K6]

Thats a casting with simple finish machining, relatively cheap for the original production run facility.

Obviously more time consuming to machine from billet.

I bought a small but reasonably complex component made in stainless from billet in replacement of a car part. It's a part of central locking mechanism inside a rear hatchback central locking assembly and originally made of "pot" metal by casting. No longer available at all, fragile and vulnerable too. I heard the manufacturer of them was running cnc dental production and filling (no pun intended, oh go on then  ) in vacant machine time by small batch production of items like that. Unsure how true though.

Bloody amazing cnc work though, even has little "pimples" left raised from flat surface that are used for detent location within final assembly.

[martin_uk]

Thanks for feedback and offers.

I didn't realise how expensive these are, especially in current climate of falling bike prices.

Still hoping it will turn up somewhere as I have a number of project on the go and parts in many locations.

What goes wrong with them ?

[Johnny4428]

The securing lug breakers off them because there is a design fault with either the engine casing or the drive itself. The top part of the drive that the screw attaches to engine rocker cover does not fit flat against each other in other words there is a small gap which if not filled with something will put a strain on the weakest part when the screw is tightened and SNAP. Don’t have any logical explanation why it was designed this way.

[martin_uk]

The securing lug breakers off them because there is a design fault with either the engine casing or the drive itself. The top part of the drive that the screw attaches to engine rocker cover does not fit flat against each other in other words there is a small gap which if not filled with something will put a strain on the weakest part when the screw is tightened and SNAP. Don’t have any logical explanation why it was designed this way.

Thanks, very helpful

[Johnny4428]

Sent from my iPad using Tapatalk

[K2-K6]

The securing lug breakers off them because there is a design fault with either the engine casing or the drive itself. The top part of the drive that the screw attaches to engine rocker cover does not fit flat against each other in other words there is a small gap which if not filled with something will put a strain on the weakest part when the screw is tightened and SNAP. Don’t have any logical explanation why it was designed this way.

Something like this is ordinarily used when one component has to float with the seal arrangement here being able to accommodate that.

Did it have a dedicated bolt, with shoulder type arrangement incorporated as original ? That could be part of the design.

A little like a rear brake torque arm bolt that incorporate such arrangement to facilitate and accept movement in use, while still being tightened securely.