My lawn mower SUCKS. Its got a Briggs and Stratton 4 stroke flat head engine, its rated at 6.75 ft. lbs. torque. Its a mulching mower so that puts more load on the engine than a bagger, but this thing has NO BALLS, it stalls from load more than it should, at least I think it does. I've checked the governor, it works fine. I stretched the throttle spring so it runs at a higher RPM sorta like giving the engine a running start before the governor tries to recover RPM. Problem is I believe the engine doesnt have enough balls (torque) to recover When the cutting RPM was stock, and the engine would experience a load, it would stall at the drop of a hat even when the governor tried to recover RPM, it just doesnt have enough stank. With the cutting RPM raised, it doesnt stall nearly as much, but its still gutless. On the flip side, my 10 H.P. snow blower really muscles thru heavy wet snow, you can hear when the governor is active, the exhaust sound get a very distinct POW POW POW POW "YEAH BABY" Should I address the carb, install a turbo, a Buick V6?????????
Check the keyway on the flywheel. If thats sheared or even "stretched" the timing will be off. One good whack and stall is all it takes.
Last year we needed a new lawn mower and I was so sick and tired of messing around with the old gasoline powered mowers. I'm a handyman and I use the 18 volt makita platform tools. And makita makes a great 36 volt lawn mower. I bought the self propelled model that makita offers and it works great! Best thing I love about it is, as long as batteries are charged its ready to go! No messing around with gas or cleaning the carb, or the stupid spark plug needing cleaning cause it's fouled out. I won't be going back to a gasoline model anytime soon. Keith
Have you considered a bigger cam and porting the head? Maybe even a turbo. My costly Honda mower isn't nearly as strong as I feel it should be.
It’s maybe 8 years old. My mower before this one was a work horse, NON self propelled, 5 hp mulcher, only reason I gave it away was the deck rotted out.
Be sure the blades are sharp, that'll reduce the load. Maybe go back to conventional blades. Wonder if the fuel mixture is off? There are mini-bike performance mods you may be able to do, like raising the compression.
You didn’t say if it’s a push type or ride on, hp? I had a zero turn Briggs powered and after only a couple of years it was doing wired things, popping noises etc. after some troubleshooting and compression check it took the head off and the head gasket was blow. I think it was 12 or 14 hp single cylinder. Really disappointed in the Briggs after that and got rid of the unit. My new zero turn with twin cyl. And more HP..was hard starting from day one, turned out the dealer didn’t set the throttle cable properly so the choke wouldn’t close entirely.
Push mower, they don’t list HP on the small engines, they list the torque nowadays, but I’m assuming it’s 5 hp Seems to me the small Briggs and the Tecumseh engines were more powerful years ago. I’m sure these newer engines are tuned (lean) for emissions reasons
I bought a JD E-140 about a year-and-a-half ago. It has a 22 hp B&S and that is plenty. I gave away my previous rider, a JD L-120 with more then 1,000 hours on it when the starter STB. I was beginning to have parts acquisition issues. The plastic intake manifold warped and wouldn't seal properly. The manifold had been discontinued, and they had a "replacement" manifold that didn't fit. Included was an "installation kit" that did not provide everything that I needed. I spent about three hours fabricating and installing parts that were not supplied. I vowed at that time that at the next big expense it would be gone. When the starter croaked I put it in the front yard with a "FREE" sign on it. If I could have purchased the proper parts for it I would still have it. The thousand-hour 20 hp Briggs still ran strongly and used no oil.
A lot of those Briggs and Stratton engines use a plastic carburetor. It doesn't take hardly anything to plug one of those orifices, especially if you let it sit with ethanol gas in it. Take the pull cover off, (8MM socket) remove the gas tank and line from the bowl.; Drain fuel into clear glass or plastic container, check for ANY sediment or water. remove the filter cover and filter to access the 2 screws (8MM socket) and 2 screws (7MM socket). The carb will simply pull off, and remove the link to governor. Clean out all off the orifices with the wire from a bread twister, no special gage things needed. blow out with parts cleaner. DO NOT USE LACQUER THINNER!!! Check the needle on the float by removing the 2 screws on the bowl. I've seen debris get there and raise all hell; also the tip may be deteriorated by ethanol gas. Reassemble, using a little oil on the gaskets. Good luck!
Also, check that the fuel tank vent (which goes into the filter housing is not plugged or restricted. That would cause very loss of power, as the carb can't suck fuel into the bowl. Actually, it only DRAINS into the bowl through the needle and float assembly...
