how can i fix my mower briggs stratton classic?

There's no such thing as a mixture screw on a Briggs Classic engine. First answer is correct.

pleasant
September 2008

Sounds like it's running way too rich, try adjusting the mixture screw. The choke could be sticking or broke, check the linkage and springs. Make sure the air filter is clean.

Mark
September 2008

Carb diaphragm needs replacing. Easy job.

Primer Start

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-electric start engines there will be a spacer - don't lose it.
3) Manoeuvre the whole assy off the engine, unhooking the throttle from the governor vane as you go.
4) Unscrew the carb from the tank (5 or 6 screws, depending on the model. Separate 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 link as you go. DON'T twist the governor 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 likely
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).

Auto-Choke

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-electric start engines there will be a spacer - don't lose it.
3) Manoeuvre the whole assy off the engine, unhooking the throttle from the governor vane as you go.
4) Unscrew the carb from the tank (5 or 6 screws, depending on the model). Separate the carb and tank.
5) Remove the choke link cover
6) 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 (if fitted), Connect the choke operating link to the choke butterfly).
7) Position the tank on the carb. turn the whole assy right side up and insert the screws. Push the choke butterfly beyond the fully open position as far as possible. Tighten the screws evenly. Don't overdo it. Flip the choke butterfly back into the normal position. It should close completely. If it is obviously binding, the link may need adjusting.
8) Install the assy onto the engine, making sure that you hook up the throttle link as you go. DON'T twist the governor 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 likely
cause of problems is a twisted spring.
9) Re-fit air filter and test.


phil_saunders@bigfoot.com

Phil Saunders
September 2008