The diaphragm on a Briggs & Stratton 550 lawn mower motor a part of the carburetor. A carburetor’s job will be to collect the fuel and mix it with air before sending it to the motor. It provides different ratios of air and gas, based on the running speed. The diaphragm can help to modulate the fuel in the mixture. When the diaphragm is awful, the lawn mower won’t run smoothly.
Signs of the End
The symptoms of a poor diaphragm are similar to other mower issues. Refusal to start or cutting during running might be the very first symptom of a problem. The mower might smoke excessively or sound sluggish. At high rates, the engine is far more inclined to give out or seem like it’s flooding or starving. Conversely, the idle speed could be higher than normal and the mower might rise up and down by itself. The indicators aren’t exclusive and a mower might have any combination of those.
What Causes It?
The diaphragm is made of a rubbery material. With constant exposure to fuel and heat, it may stiffen or dry rot. It has to remain flexible to do its job correctly. Going bad might not have anything to do with something you’ve done wrong or defective parts, but is probably caused by standard usage. If the diaphragm becomes stiff or cracked, it will place an excessive amount of fuel into the motor. The excess smoke that accompanies it’s fuel burning, while the revving and discontinuing results from flooding in the motor.
How to Fix It
Luckily, a diaphragm could be replaced without replacing the whole carburetor. To get it, you must remove the air filter and the bolts holding the carburetor on the mower. The carburetor is in addition to the fuel cylinder or right next to it, based on which string of the Briggs & Stratton 550 your own have. Screw off the base of the carburetor to reveal the rubber gasket and diaphragm. 1 corner of the diaphragm has a spring. When you shake it in, it should bounce back and have good spring. There shouldn’t be any cracks and the remaining part of the diaphragm ought to be pliable. If it’s rotting or has some damage, pry it off and replace it with a new one. Carburetor rebuild or repair kits will offer a new diaphragm as well as other replaceable parts.
Other Culprits
A few other lawnmower problems might have a number of the very same symptoms as a bad diaphragm, especially the difficulties with beginning and sputtering. A poor spark plug can result in many issues. This is one of the simplest fixes, because all you need to do is unscrew and replace the spark plug on the exterior of this mower. The starter assembly might also have some complications. The rope should pull smoothly and start the internal spinning inside the first few inches of string. If it does not, the rope might be attached or the spring might be broken. Inadequate compression might also be at fault. Briggs & Stratton recommends visiting an authorized service center for compression testing on its engines.