Outdoor Power Equipment and Small Engines - B&S 4hp Quattro

I have a briggs & stratton 4 hp Quattro that has just started acting up. I seems to be running to rich because it is putting dark smoke out the exhaust and running rough. Could anybody please help me with my problem?

Check your air filter, if its very dirty it may need to be replaced, also if you have a manual choke on your engine it could be sticking and not opening all the way. If all that checks out then the next thing to look into would be the carburetor.

Model, type and code numbers off of your engine would be helpful.

Hi 30 Year Tech

Sorry about getting back to you so late on my B&S 4 hp quattro. I clean my air filter every year with soap and water then I oil it up and squeeze the excess oil out. I don't have a choke on my mower that I am aware of. Here is the info on my engine.

Model: 10A902
Type: 022101
Code: 96121655

I would appreciate any help you can give. Thanks

You need to install a new diaphram kit, it is Briggs part # 795083 or old # 495770 also Lowe's has a kit #5083 which has the same parts.

Here we go;
Remove air cleaner, there are 2 bolts that hold things together, one on the front of the tank 3/8" and one into the block 1/2", remove these bolts, now "slowly" slide the carb/tank off the intake tube and breather tube, now tilt the tank in to release the throttle linkage and waalaa the carb/tank is removed. Remove the 5 screws from the carb/tank remove carb(don't loose the spring) now spray all holes, cracks and crevases in both the carb and tank surface with brake parts cleaner, remove the main screen(looks like a thimble) with a small screwdriver pry out the main jet(carefully) and clean it, reinstall the jet, it can be difficult some times to get it to snap back in place(I use the rounded end of a screwdriver handle). Remove and clean the fuel pickup stem. Clean any junk/rust from the tank. Install the diaphram on the tank then the gasket(no goo or sealer) now carefully replace the carb(the spring will try to misalign the diaphram), tighten all screws a little at a time so as not to crimp the diaphram until they are all tight. Install the carb/tank in reverse order and you are done. If I missed something one of the real mechanics will correct me. Have a good one. Geo

The numbers help let us know what your working with.

I recommend that you follow geo's advice on your engine.

Best of Luck...

Thanks you guys, I will try and get the new diaphram this weekend. I will let you know how it goes. I really appreciate the help.