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Hi. I recently purchased a Navigator and on inspection discovered it was leaking oil badly from the oil return pipe. The pipe runs along the top of the front sprocket and appears to have been in contact with the chain, splitting the pipe and causing the leak. Is this routing correct as it seems to be a problem that will reoccur if replaced. I can't seem to find a routing picture anywhere. I've attached some pictures for reference. Thank you
Hi Philip,
Suspect you have a pre-64 Navigator. This has a breather pipe attached with a union to the crankcase at a position in front of the gearbox sprocket.
The NOC shop has images of 23367 breather pipe and 22314 union. Use the search facility by part number on the NOCshop to find them.
Observe the the breather pipe is cranked.
I suspect that your breather pipe has been attacked by a broken chain in the past causing the damage seen on the photo. Sometimes the union can loosen and the pipe rotate so the outlet is above and very near the chain. It can get bent. The breather pipe outlet should be set inboard and above the gearbox sprocket, and the union tightened.
Sketch attached.
Some rubber breather pipes rot with time and split anyway. Attacked by oil and grease from the outside, and the vapours inside.
You might get away with a new pipe and clip as the chain will not flay around, where it goes over the sprocket. The damaged pipe end won't help you. Hoping the pipe isn't fractured inboard or the union loose.
Or bite the bullet and check. Maybe renew. You will have to remove the primary drive covers. This entails much more and you should get a Norton Twins workshop manual. Be prepared to borrow or buy the extractors and holding tools for clutch and crank sprocket.
Welcome to the wonderful world of Norton Lightweights.
Peter