Navigator Breather

Hi Steven, Yes itâs the crankcase breather. Thereâs a few threads on this, have a go with the search facility. Thereâs one here:https://www.nortonownersclub.org/noc-chat/technical3-light-twins-forum/319906982

Mine has a short length of copper pipe pressed into the hole, which I think is original, there doesnât appear to be any threaded nipple or similar to hold it in as there is on the earlier engines. Thereâs a pic of mine in the thread link Iâve copied above.

As a short fix I expect jbweld would hold the copper pipe in there

dan

Hi Steven, on my original late 1964 Navigator the crank case breather is just a length of metal pipe a couple of inches long fitting into that hole - I've never removed it so I don't know if it is threaded in or a shrink fit. A rubber pipe fits on to it and leads up to the front of two short metal pipes let in to the top inside face of the oil tank. The second pipe is for a rubber pipe which leads down to a hole at the front of the chain guard and acts as a chain lubricator. The earlier Navigator and Jubilee had a similar oil breather pipe in the same place but if my memory serves me right it was held in by a screw in collar. Sadly I don't have a picture and I couldn't find one on the internet - perhaps someone else can help.

Regards

Nick

Hi again Steve, Dan's picture shows a pipe rather different from mine which is much shorter and comes straight out of the crankcase and only projects about 2" past the casting above the final drive sprocket. It appears to be shrunk in. I was right about the earlier engines, they had a metal pipe held in by a screw in collar. These are available from the NOC shop - I have attached the pictures from the shop page to give you an idea of what it looks like.

Nick

The pipe on the earlier engines were in a different place, just above the gearbox sprocket and hidden between the cases, it was a pita to get at, and prone to chain damage. My guess is that they were pressed in when the cases were hot, but you could solder or glue.

Dan