Hi Everyone,
My neighbor has a Sears push mulching mower. It is starting to slow down whenever it gets hot. It runs great until it gets hot. I thought I read somewhere that the magnetron may be the reason. Am I right? The mower model number is 917.388541. I couldn't find the part number at Sears, so I went to Briggs. It is a 5.5 hp Quantum, with the following numbers:2BSXS.1901VH. Also, 123K02-0314-E1-04051758. I feel pretty humble right now because I can't seem to figure out the B&S website well enough to get the proper parts list. I'm trying to get a price of the necessary part for my neighbor. If I had any hair I would pull it out. Thanks for any help you can lend me. Ron

spiffybrit@cox.net

Magneto not properly timed can cause overheating. Also, carbon buildup in combustion chamber can cause it. When was the oil changed last? Has it been serviced? Is grass clogged up all around it?

Do you have a napa auto parts store around you? can't remember exactly on the coil, but they have started selling b&s parts (and coils) there. The mag itself just bolts on, not timing, if the flywheel key was sheared, would be hard to start if slightly, wouldn't think you'd be able though.....
carbon build up would make it hard to start.....

Try a new plug right quick and see how it acts, and or pull the gas cap real quick. But by starting to slow down, does it run great then run at a lower speed? but STILL run? or just cut out?

Thanks for the suggestions. I haven't checked for carbon buildup but I will. No grass buildup. Mower looks to be only 2 years old (or so) but as far as I know no one has serviced it until last fall when I changed the oil, changed the plug, air filter, sharpened the blade and checked the carb bowl for water. It ran good all spring. Thanks for the suggestions. I will check them out. Ron

There's a NAPA a mile away. Will check for a coil price after I check the flywheel key and put a new plug in it. The plug looked good, but it is a Champion so it's worth a try to replace it. It slows down but does not die out. Never thought of the gas cap vent. It was OK last fall when I saw the mower last, but didn't check it out this time. Sounds reasonable. Thanks for your help. Ron

if napa doesent have your ignition module then go to sears and get a Div 71/ Pls 500- part# 802574

Thanks inch. That is a tremendous help. Ron