[Fot] New? HS6 failure mode

[Phil Gott]

While running my TR4A on a dyno the rear carburetor piston spun in the housing. The little “L” shaped guide that positions the piston came loose. The small Screw (probably a Whitworth(?) size between our numbers 4 and 6 machine screws) Apparently worked it’s way out If it’s hole and into (and hopefully out of) the engine.  This screw is set into the carburetor body and held in place by a split end - similar to a butterfly throttle screw.  I found the “L” shaped guide lodged into one of the breather holes in the carburetor body.  The screw is visible at the front of the carb body if you remove the air dome and the piston.
I have never serviced these screws: have overlooked them in fact. It would seem advisable to remove these, clean them up and then Loctite them in place.
Another lesson learned the hard way....
Phil Gott 

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