Odd screw

[coater87]

 Guys,

 I have cleaned up the cases, and was going to shell blast them today. After cleaning them I noticed an odd screw near the timing side bush- I think I remember this being a spring and ball check valve. But I am not sure if my memory is correct here.

 Is there good reason to remove this, or maybe it is just an oil gallery plug and should be left alone? I am curious as to whats behind "door #1", but I also believe the screw will not survive this. If I do have to remove it, does anyone know the part number as I cannot find it in my meager "wish books".

 Lee

[muskrat]

You are correct it is a check valve and it would be a good idea to at least clean it out. I have seen them on eBay (njavery) in UK I recall.
Cheers

[coater87]

 Hi Muskrat, and thanks for the reply.

 I found the ball and spring on e-bay alright, so I am set there. I am most worried about the little screw itself- seams mine was peaned over in the same manner as the sludge trap plugs. I dont think there is any way I will get it out and be able to save it. I did not see that part on e-bay, and its not listed in my parts books.

 Any thoughts?

 Thank you,

 Lee

[olev]

Lee,
Its an interesting one. This is the valve that prevents wet sumping.
I wrecked the bung getting it out of mine but had no problem getting another.
The spring was a different matter, mine was stuffed and in 2 pieces.
The new spring I got from njavery was an mcs brand and looked nothing like the original.
The next one was from the local bike shop (also an mcs) and was very very stiff and nothing like the original.
Maybe both would have worked but this really high lighted to me the variable quality of the spares we buy.
I finally got one I'm happy with from a wild old hairy type at a swap meet. (with a personal guarantee)
The BSA service sheets tell you not to disturb this screw. From where I'm sitting its just as well I ignored their advice.
The later model A65's fitted this valve under the oil pump where its accessable.
Its your call Lee, but unless you have better luck than me, prepare for some fun.
cheers
ps: thanks for the lead on the bottom end , but it all got too hard.

[Dynamo Regulators Mike]

Hi Coater87
I fully agree with Olev, open the door.
When I took mine out the lightweight spring was in 2 pieces. But a good cleanup and new replacement ball and spring will eliminate most 'wet sumping' or drain down (apart from leaks past oil pump gasket and shaft. And look how many times that issue comes up.
DO take care with getting correct weight replacement. I think I got mine from Draganfly but Lightning spares, C & D for example should also be reliable source. When sorted no need for feed line taps or aftermarket valves.
Cheers
Mike

[coater87]

 Well guys,

 I absolutely destroyed the screw getting it out. I could not believe how deep the peening was, seams someone fifty years ago had an "angry face" on, (thats what my 8 year old daughter calls such moments! ).

 Now I need a new screw (or need to know the thread size- as all I have is a bent up lump left)- and a part number for it if possible. I have read on the forum about the A65 valve, but no really good explanations on it. If I go with the A65 set-up, what do I need to modify or do?

 My spring was in one piece, and I suppose with a clean-up I could re-use it after grinding the ball in for sound mating. The big one here is the screw. I am willing to make this if I have to, but I need to know all I can about it, or an SRM part number, or any other help. I am stuck in the mud until I get this sorted.

 Lee

[scotty]

Lee

you're doing the right thing in replacing the anti syphon assy while she's all laid bare

i recently replaced mine and got the parts from British Cycle Supply in NS canada.
i think they also have a store in hackensack NJ.

here's the part no's

67-1401 oil retaining ball grub screw
67-1400 oil retaining ball spring
1 4675 oil retaining ball

scotty

[coater87]

 Scotty,

 Thanks!!!! That is exactly what I needed to know, and BC is not all that far as shipping goes.

 Lee

[olev]

Lee,
I remember reading somewhere (could have been on this forum) not to grind the ball in with paste.
Its better to sit the ball against its seat and give it a couple of sharp taps with a rod and hammer.
Apparently this does the job admirably.
maybe someone else can comment on this?
the size of my sharp tap might differ to others.
cheers

[RichardL]

Olev,

I confess, I was one (perhaps the only one) to suggest grinding in with paste. I can't say I know it's better than a tap, but, having lapped in a lot of valves, it seems to make sense, to me, at least.

Richard L.

[orabanda]

Olev,
Youv'e got it right brother!
A light tap, using a drift which is softer than the ball (mild steel or copper is very good). Don't hit the ball excessively hard, as the crankcase is soft (aluminium) and the seat could be damaged.

We use this technique daily in the fluid power industry.

Richard