oil feed and return pipes & hose

[56G80S]

As part of the re-assembly of the Matchless G80S 1956, I looked at the oil pipes; mine are all copper.

There were some cuts, nicks and abrasions which I thought could compromise their integrity over the relative short term. So I cleaned the worst, Bakers fluid and small torch ran in some old style plumbers solder and flatted back. I thought I'd get some new hose for connection up at the tank.

The thing is that the feed pipe isn't 1/2" but actually 7/16" while the return is 3/8" and sleeved at the tank end to a full 1/2". Why does this matter, you ask? I had thought to cut the copper pipes to a stub at either end and fit hose. It would make the connections to the crankcase more straightforward and reduce the likelihood of damage. The way the copper pipes are routed makes doing this very awkward. Getting around the centre stand, gearbox and frame rails is very cramped and for some reason, although they've done the job since the mid 1970's, the pipes not only don't want to fit in the space but no longer seem to line up with the tank as well as they should.

However, hose is even bulkier and would need some clips or similar to keep it to shape! In any case, finding good fitting hose is not going to be easy, in my internet searches what's available is metric equivalent, although the metric equivalent to the 3/8" seems quite close. For the feed pipe, 7/16" but supposedly 1/2", I have in the past simply wound the jubilee clip up tight but it's never been really satisfactory and weeps quite a bit.

Thinking by keying in really.

I never really thought about it when doing this previously.

Cheers

Johnny B

[Groily]

I replaced copper pipes on my twins - for all the same reasons - with neoprene with imperial 1/2" id from AMC Classic Spares. Dunno if the dimensions are the same for a single, but worth an 'ask' I'd say. Cost about 50p an INCH when I bought my bits, but you don't need yards. Doesn't even need clips on the ends, they say (although I added some).
Gets round the double diameter thing, gets round the flexibility or lack of it thing, and as my original pipes had an outside lining in black stuff, doesn't even look wrong. Darn sight easier to fit a tap in the feed too, for them (me) as wants.
But as IKBA about singles, maybe not a runner.
All I can say is 'Success' on a twin, for which I had various sets in copper lying about, none of them an easy fit. I'm happy anyway.

[56G80S]

Cheers.

I cut the 3/8" return pipe this afternoon so there is a couple of inches of stub to fit hose onto. Maybe it's the combined effect of the carpal tunnel in the right wrist, chemotherapy or just old age but I tried fitting it. Alignment was very difficult and having tested before re-assembly of the crankcases I knew it should turn in with fingers only.

I'll tackle the 1/2" pipe tomorrow.

On the neoprene, Steve Surbey at AMC Classic Spares had sent me some previously following a very helpful conversation. As I said earlier, my pipe is really 7/16" (not just my measuring error, it's slack). I may use 1/2" to sheath the copper pipe that suffered abrasion damage, using two jubilee clips at the tank end but also another at the crankcase end as if the crankcase were a stub.

It's a lot easier to do with the timing side footrest removed!

Johnny B

[Trefor]

I've used 1/2 petrol pipe on oil lines (10 years +) with clips. As the pipe here comes from the US it is still in imperial size.

[56G80S]

Thanks for the information. The 1/2" hose from Steve at AMC Classic Spares is a perfect fit on the tank stubs, but for my feed pipe is a bit slack, just have to tighten up the jubilee clips a bit more, but not so much that they cut into the hose.

Johnny B