The most important part of rebuilding SUs is to make sure the jets are
centered. Do this by assembling the jet assembly and install it in the carb
body with the jet locking nut (the large one under the carb body) finger
tight. Then assemble the needle to the piston, being sure that the shoulder
on the needle is level with the bottom of the piston. Assemble the piston
to the dashpot WITHOUT THE SPRING and install the dashpot on top of the
carb. Do not put any oil in the dashpot yet. Now, hold the carb with the
needle axis vertical and lift the piston and let it drop. It should drop to
the bottom of the carburettor throat with a metallic "thunk". If you do not
hear this sound, loosen the jet locknut and retighten, while cycling the
piston and repeat until you hear the aforementioned "thunk". At that point,
the jet is centered and the locknut can be finally tightened. Check once
more, then remove the dashpot, install the spring, reinstall the dashpot,
replace the carb on the manifold, and fill the dashpot with oil to about one
half inch from the top. Now, you can tune 'em. If you need help with this
stage, e-mail me offline...
-----Original Message-----
From: Malcolm Walker <walker05@camosun.bc.ca>
To: The Usual Suspects <triumphs@autox.team.net>
Date: Saturday, September 04, 1999 2:12 AM
Subject: SU rebuilding tricks?
>
>OK, I'm almost ready to start rebuilding my SUs. I couldn't find a book
>locally (at library), and can't afford to buy the proper one, so I turn to
>the 'net for help.
>
>The only Sneaky Trick I've found so far is to soak the cork gaskets in oil
>overnight so that they're pliable. (The cork gaskets got dunked tonight).
>Is there anything else I should know? Or is it basically a tear-down,
>re-assemble job?
>
>TIA,
>-Malcolm
>* There is a FAQ for this list! Its new home is:
>http://www.islandnet.com/~walker05/triumph/trfaq.htm
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