I am looking for a crankcase breather option, other than the very nice but pricy NYC one. I have seen some mention of "New reed breathers" on this forum, but all the links are no longer active. Older posts. anyone have any suggestions for a nice easy bolt on.
1970 Commando crankcase breather options
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marshg246
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Sump reed valve breather
Replace your sump plug with this one way reed valve breather to reduce oil leaks and pump out excess wet sump oil on start up. Fits all Norton Twins with a large screened sump plug.
jsmotorsport.com
o0norton0o
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You have a '70 commando. Your bike's frame has a frame rail in a different spot than later model commandos. That frame rail is right next to the engine drain plug and prevents the use of the "pricey NYC norton" sump plug breather because it partially blocks the larger part of that breather.... It might also block the use of the Jim Schmit version of the sump plug breather as well. You might want to call and ask Jim before ordering it from him...
Either way, Jim sells a reed breather that screws into the camshaft breather port on your '70 crankcase. (I use it) I also have a 2nd reed breather mounted on the timing cover plate for dual breather performance...
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ran into this problem recently. I highly recommend the AN #13.1743 magnetic crankcase sump filter kit. It was a bear getting the old one out and installing the new one but this kit gives a thin wrench to do it. Otherwise there is no way to drain the sump.
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Andover Norton - MAGNETIC CRANKCASE (SUMP) FILTER KIT - 06.7281
MAGNETIC CRANKCASE (SUMP) FILTER KIT
andover-norton.co.uk
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Eric, there's quite a bit of discussion on this topic in the thread "Yamaha EGR Reed Valve Breather Hack '74 MK II Completed (almost)"
My preference is an in-line reed valve from a small motorcycle air injection system.
As usual, everyone has their own theory regarding source, type, placement, etc.
My preference is an in-line reed valve from a small motorcycle air injection system.
As usual, everyone has their own theory regarding source, type, placement, etc.
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A trailer hitch ball wrench fits perfectly - no slop - and gives lots of leverage on that drain. I forget which end, prob 1.5" not the 1.75". I stumbled onto that. I have that drain plug fitted, so the only time I have to use the big wrench is to check the screen. So far, 1K miles on the engine I rebuilt (66 N15CS) with stock breather apparatus and no paper filter (yeah, I know...) it's never had anything of consequence in the screen, and no breathing issues. Knock wood of course.
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