I have a JD LA135 22HP BRIGGS V-TWIN model 407777-0188-B1. Initial problem was the fuel pump stopped working and I replaced. After replacing and mowing a few times it then started to pop/backfire. I replaced the carburetor but problem did not change. I have since replaced the gas, the gas cap, spark plugs, checked the compression and valve settings, new air cleaner, all of the gas hoses and filter, One of the two coil/module, checked for shorts, removed the wiring harness with the diodes from the coils thinking the diode was bad but it was not. I at one point pulled one plug wire and started the engine and the popping and backfiring stopped. Did same on other side with same result. So I can run on one cylinder without backfiring but not on two.
I am at a total loss as to what is causing the problem. Any help?
I am at a total loss as to what is causing the problem. Any help?