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Oil leak


Hi everyone. I need to buy a new oil seal for my Navigator but don't know what it's called, can you help please. It's located on the top of the left hand engine casing, when sat on the bike, where a black wire goes into the casing. Oil is oozing out and drowning the drive chain. I can then order one from the Shop.


Andy James.




You're looking for the contact breaker lead grommet (my description because it's not in the parts list I have). It's also not in the NOC shop because I've just looked. There is an alternator lead grommet which you might try but it's going to cost over £10 to do that and it might not work. Probably the best option is to use some silicone sealant to seal the lead from the inside of the timing case.

Good luck, David


Hi Andy,

From your description I believe your oil leak is behind the cylinders (left hand) on top of the crankcase where the alternator cable leaves the primary chaincase. 

You need a new alternator output cable seal. The club offer part number 08163 which suits the earlier Navigators. You will have to remove the primary drive outer casing so maybe you need a new gasket for that too. Lightweight parts/Rubber parts/ 08163 at £7.95. I think you can just feed the bullet connectors with wires through one at a time. Silicone sealer is a useful addition. Fit the seal into the chaincase before threading wires and sleeving through.

Later Navigators used a cone shaped rubber seal with 3 small holes for each wire. In addition the hole in the inner chaincase, viewed from inside, had a tapped hole for a small plate that squashed the conical rubber seal into the cable output hole for better sealing. I don't know where you get these later rubber seals from. Wires are threaded through the seal before black outer sleeving and bullets are added.

Hope you can cure the leak.



An oil leak is the bike's subtle way to let you know there's still oil inside - somewhere!  No oil leaks and a dry engine may well mean NO OIL! :-) 


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