It hasn't got a float bowl because it's not a Quantum engine. The engine you have has a non adjustable diaphragm operated carb which is mounted directly onto the top of the fuel tank via 5 cross headed screws. The fuel pick-up pipe is connected to the underside of the carb and goes directly into the fuel tank below. Wouldn't bother with the carb at this moment, but instead change the plug- they are cheap, easy to change and could break down the very next time you come to use the mower, so symptom-wise it could be at fault. Failing that you could have water in the tank. How did you change the fuel? It's impossible to get all the fuel out of this type of tank as there is no drain point- the only effective way is to remove the tank itself and tip it upside down. My feeling is if it's not the plug then almost certainly some water has got into the fuel tank. I would remove the tank, clean it right out and whilst I'm at it change the rubber carb diaphragm that's sandwiched between the carb and the tank.
It's an easy job with basic tools. You will need a 100mm socket and/or a 13mm socket, a ratchet and a short extension bar. Also a medium cross-headed screwdriver and a large flat bladed screwdriver. Go to your Briggs agent and obtain a carb diaphragm kit pt no:795083 at a cost of 70p plus vat. Place the mower on a flat surface and unscrew the bolt that hold the air filter in place and remove the complete filer assy. Take a look at what's exposed and take note of how it's assembled- by the filler cap on the top of the tank you should see a black headed bolt going into the engine (it's either a 10mm or 13mm depending on the age) remove the bolt from the engine and be careful not to drop the cylindrical metal spacer if it has one between the bolt and the engine block. Next look at the front of the engine (spark plug side) and locate the 100mm black bolt at the front of the carb- remove this one as well. The tank is now free from the engine effectively- you now need to look at the top body of the carb and you will see a delta shaped piece of plastic that you can move side to side, In this plastic you will see a metal rod hooked into it the have the govenor springs attached- you do not need to unhook any springs! The next proceedure entails you clasping either end of the tank and slowly pulling it towards you and whilst doing so lifting the front of it up so the dog leg end of the metal rod in the plastic unhooks. Once unhooked you should have separated the tank/carb unit from the engine. Place the tank/carb on a bench and gently undo the 5 cross screws retaining the carb to the tank. Once undone take a grip of the carb and split the carb from the tank (be careful you don't lose any small parts) You will now see the diaphragm and gasket on the underside of the carb- gently pull these off the base. Tip the tank upside down and flush out with fresh fuel. Thoroughly clean and dry the mating surface on the top of the tank and inspect the carb and tank for evidence of water or foreign bodies. If OK, place the new rubber diaphragm onto the top of the tank, followed by the gasket. Gently lay the carb on top and place the screws into the holes of the carb- ensuring they go right through into the carb thread- and are not catching the diaphragm and gasket. Evenly tighten these screws- top up the tank with some fuel and test the operation of the primer bulb. If OK the carb will emit a spray of fuel. Re-fitment is a simple case of reversing the removal proceedure. Before re-starting the engine and putting the filter back on- ensure the delta shped piece of plastic moves freely and is not caught up by the dog leg metal rod not re-fitted correctly. Start the engine and see how you get on.
pleasant, August 2008
