Easy job ;-
1) Remove air filter
2) Remove 2 bolts securing carb/tank assy to engine. One at front of engine,
and one just in front of the tank filler. On non-electrc start engines there
wll be a spacer - don't lose it.
3) Manoever the whole assy off the engine, unhooking the throttle from the
govenor vane as you go.
4) Unscrew the carb from the tank (5 or 6 screws, depending on the model.
Seperate the carb and tank.
5) CLEAN the tank surface. Place the new gasket and diaphragm in position on
the inverted carb, making sure that the fuel pump spring and cup are in
position.
6) Position the tank on the carb. turn the whole assy right side up and
insert the screws. Tighten them evenly. Don't overdo it - the carb is
plastic.
7) Install the assy onto the engine, making sure that you hook up the
throttle lnk as you go. DON'T twist the govenor spring - check that the
throttle moves freely. If it does not, FIX IT NOW - otherwise the engine
will attain some really impressive RPM's before self-destructimg. Most likly
cause of problems is a twisted spring.
8) Re-fuel, and check that the primer squirts fuel into the engine (you can
see it by looking down the air intake). If OK, fit air filter and test. If
not, either the diaphragm was damaged during fitting, or there is a stuck
check valve in the carb. If a sharp tap on the carb body doesn't fix it, a
replacement carb will be needed (not likely, but possible).
Phil Saunders, August 2008