1954 NH first proper shake down rides

[Gui.dorey]

After finally getting the bike registred for road use, I’ve been doing the first longer rides after the rebuild. Managed to drop some nuts and bolts during the first rides, but no major problems.

However, I’ve been fighting with two issues which I haven’t been able to solve despite some long hours fettling with it.

One is a major oil leak from the timing chest to the magneto. I put in the mod with a pipe from the timing to the crankcase and a higher oil passage in the cam case and a paper washer behind the mag sprocket, but all to no avail. Why is there so much oil in the timing which must be thrown up by the chain and out to the magneto, I've no idea. And, yes, I have a timing case breather pipe, out of which only a mist comes out, and the pump is working well returning to the oil tank.

The second problem is the clutch slipping. Especially at higher rpms, and when accelerating. This ends up resulting in a very poor performance and I can’t really open up the throttle fast when accelerating. I have a 2 plate clutch and ferodo inserts and new springs from Drags, which are the stronger ones. At first I had installed some plates which I had bought from Draganfly over 20 years ago, and they really were terrible. I then installed some old ones I had lying around, which improved a lot, but the slip is still there. All manner of adjustment hasn’t led to any improvement. The plates are clean and free of oil, so the only thing I can think of next is to try going back to cork, but I’ve got to get hold of some.

As always, any thoughts are very welcome.

Cheers
Gui

[simon.holyfield]

Have you tried cleaning up those plates with some sandpaper on a sheet of glass or something flat? They look a bit glazed to me.

Second question - is the plate in the second picture really a Ferodo plate? it looks like cork to me, in which case you could get some new ones from Geoff Brown.

[Gui.dorey]

Hi Simes,

I did it with sandpaper the first few times. The plate in the first picture is now glazed again after the last time I took it out. It was slipping so badly I was nudging it home at 40 kph.

The 2nd plate is probably an original cork one, but the inserts are now some kind of ferodo-like material. Done by some previous owner so I can’t tell you what it is.

[Simon.Gardiner]

I've got original plates with ferodo/other non-cork inserts that look like pic 2.

I've tried using various non-cork plates - new ones. old ones, sandpapered ones, degreased ones - they've always slipped no matter what I do with the springs so for me it's cork all the time. Which I don't have any problems with.

I also seem to get oil pushed through the mag and dyno - it doesn't drip out but things get very oily. This is across 3 different singles, with/without the timing-chest oil level mod, always with the paper 'flinger', always with a working timing-chest breather. I've decided my expectations are too high in that area although right now there might be some excess piston blow-by contributing....

SG

[will_curry]

I'd expect a VH to have a three plate clutch - does it still have the three plate centre?

Ferodo is more likely to slip than cork at the best of times - its advantage is that it
doesn't burn out.

i have a road-going HS on 350 gearing and a three plate ferodo clutch. The clutch
doesn't slip but oil comes out between the mag and timing case when i rev it hard.

I'd try another plain plate at the back of the clutch if there is room just to pack things out.

[paul.jameson]

Are you using an Ariel oil pump or a Morgo one?

Could the oil be coming from a partly stripped magneto platform bolt into the underside of the timing case? These are cycle thread into alloy which strips as soon as it can.

Are the slots in your clutch outer and centre unworn? If they are worn, then they can prevent the plates from seating properly. Have you got the clutch adjustment correct or could the end of the operating lever in the gearbox be tight against the cover or the oil filler cap? You need to have some slack there with the cable disconnected. Adjust using the adjuster on the gearbox end if necessary.

[Gui.dorey]

I'd expect a VH to have a three plate clutch - does it still have the three plate centre?

Mine’s an NH so it has a 2 friction plate clutch. But I might try your idea with the extra plate just to see if it improves things.

Paul Jameson, it’s not that bolt. Mine is actually not stripped. Oil actually forces itself into the case for the mag to dynamo gears and comes out between the dynamo and mag. Most of it comes out the bottom of rubber ring between mag and timing case and seeps down all over. If you zoom in the picture above, tou can actually see oil drops on the ground below the bike, and this was just the time to stop, dismount and take the picture.


The slots on the clutch drum and hub are somewhat worn of course. I cleaned it up as much as possible and checked several times that the plates move freely. Could be that, but I believe they are sliding in and out well enough. As far as the adjustment goes, I’ve given it plenty of slack and some more - both on the adjuster on the gearbox as on the cable itself. I also checked and made sure the internal lever wasn’t fouling against the inspection cap. All seems good there. The clutch rod and ball also are moving freely and not catching.

[will_curry]

I wonder what made me think it was a VH . . .
. . . when it's so obviously a very tidy NH.

How long is your timing case breather? Mine doesn't vent much
at all at tickover but it becomes quite messy if I use the revs.

[Gui.dorey]

How long is your timing case breather? Mine doesn't vent much
at all at tickover but it becomes quite messy if I use the revs.

You can see the end just below the timing case.

[will_curry]

I think your breather pipe is too short. I'd slip a length of
petrol pipe over it and tie the other end to the bottom frame
tube. This way if there is oil coming out of the breather it will
be over the ground and not over the exhaust pipe, gearbox
and your boot.

Screenshot of the breather pipe from Draganfly.