View single post by Jim Ketcham
 Posted: 03-02-2009 01:20 am
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Jim Ketcham


Joined: 03-13-2005
Location: Salt Point, New York USA
Posts: 198
Actually, the air box was standard on all J-Hs, Dellorto and Stromberg.  The air cleaner (looks like a muffler) attaches to the air box via a ~3in hose.  There are photos in the JHP Photo Gallery one of which can be seen here:(

You can also see drawings in the parts manual and service manual.

The air box serves several important functions.  One thing it does nicely is allow vented crankcase oil vapors to condense and run back into the crankcase while providing a means for the "light boiling point vapors" to be fed to the carbs.