CB750 Oil Control Orifice (early diecast K0).

[JamesH]

Hi guys. I'm on the hunt for some unicorn shit...

Need a pair of oil control orifices / jets for an early 750K0 head. Anyone know of anyone who has there or (long shot) even reproduces these?

Pics below...

[RGP750]

If You want to risk sending me the two types i'll do some fishing
about having some made.

[JamesH]

Sorry Rich, should have been clearer, it's one type, just photographed from both sides..I'll see if Graham doesn't mind popping the one we have in the post to you...

[AshimotoK0]

I think you will need to get the holes cut with a micro laser. I get tiny, perfectly circular holes cut in three sizes in the  s/steel foils used on a scanning electron microscope unit we make. One hole is so small you can't see it with the naked eye. I get them made via my mate in Cambridge ... I can get you the details if you wish Rich ..pretty sure someone on the USA forum was planning to have those made too. Must be later K0 ...mine just has a hole ...no removable jet whatsoever. Obviously, this had been debated before on here.

You could also sell that part to fit onto the spout of a dollies watering can 


update see here:

http://forums.sohc4.net/index.php?topic=154725.0

[Phil k]

Is that a 12238-300-300? I have one that I purchased in error a couple of years back. If you still need it.

Phil


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[JamesH]

Hi Phil - could you send me a picture of it. If it looks like this I'll take it...:

[Trigger]

The part number should be 12238-300-000

[JamesH]

Is that a 12238-300-300? I have one that I purchased in error a couple of years back. If you still need it.

Phil


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Phil - have sent you a Pm mate..

[MrDavo]

My K1 ones look like that from above, I can't see below to see if they have the watering can holes. How easy is it to get them out, as they don't respond to a gentle tug? Do I need heat?

I wouldn't mind giving them a clean out, I guess I could just clean then in situ by squirting brake cleaner through from above, followed by a blast of air.

[JamesH]

Yeah I'd be very very careful. Graham got mine out with Heat / a magnet but if they're well in there probably best left alone and try to flush them through in-situ...

[Trigger]

They have to come out to be cleaned. This is one of the main problems why the engine has no oil to the top end and the cam shaft snaps.
One way to test what jet are in the K1 is, to run a magnet over the jet. If it is the early type the magnet will pick it up as it is steel, the later ones are alloy

[MrDavo]

My K1's quite a late number, so I wasn't surprised to find the jet isn't magnetic  If had been steel in alloy, heat would loosen it, as it is, it won't make a difference.

A blast of brake cleaner and air in a can all came out of the stud tunnel, with no visible crud, and the motor was freshly rebuilt, so I'll settle for that.

[Trigger]

They still have to come out to be cleaned, the alloy type come out very easy.