B&S problem

[stmiller2]

While mulching leaves over the holiday, my Snapper mower with a two-cylinder B&S engine would suddenly lose power. When I depressed the clutch/brake pedal, the power would return.

I suspect a fuel delivery problem and will replace the fuel filter. The owner's manual shows two alternative filters: one with an internal pump, the other without a pump. The current filter has the pump. Are there any disadvantages from switching to the filter without the pump?

Thanks in advance for any advice.

 

[Molerj]

Steve, I'm assuming that you mean that the different filter is used when you have a fuel
pump or just gravity fed system. The difference in the filter is the size of the micron. You
can see some of the filters at http://www.jackssmallengines.com/oil_fuel_filters_bs.cfm.
I'm not real sure that the fuel filter is your problem. When you say it loses power, does it still run
or will it shut down if you don't push the clutch in? Could the leaves etc. have gotten
jammed up in the deck/belts?

 

[kubmech]

What Ron said about the filters. As far as losing power, It is very possible, by the way you described the conditions of the power drop off that you are simply just trying to take too much of a "bite". The mower is working hard to chew through all the leaves and if your ground speed is too high you will bog the engine. The act of pushing in the clutch slows your ground speed to a stop and allows the engine to catch up with what the mower is attempting to do. Try going real slow and see if the engine stays up to speed. Then increase your ground speed as the engine horsepower will allow. As the engine starts to bog down decrease the ground speed. This may be the only problem. And is very normal for leaf mulching operations.

 

[stmiller2]

Ron & Art,

Thanks for the information.

Regarding the filter, the owner's manual shows the filter with an internal pump -- I assume that it acts something like a syphon even though the fuel is gravity-fed.

I air-hosed all of the debris from the mowing deck. The engine would still lose power even though the mowing blades were not engaged. Unless I pushed in the clutch/brake pedal, the engine would stall completely. If I pushed in the clutch/brake pedal, the engine would recover.

 

[Bird]

I may be plumb out of the ballpark, but my first thought was a governor spring may have come loose.

 

[Molerj]

Now it sounds like a belt problem. Check your belts to see if they are on the pulleys. Have
someone else push in the brake pedal & watch what takes place under the tractor. You
can do this with the engine off to see how it works & then try with it running.
We'll figure this out sooner or later.

 

[stmiller2]

Ron,

Thanks. It will be later rather than sooner, because I will not be able to get back to my farm until December 20.

I will certainly check the belts per your suggestion.

I may not have been clear as to the symptoms. Regardless of whether the mower blades were engaged, as I was riding the mower, the engine would suddenly act as if it was going to
die.

If I pushed in the clutch/brake, the engine would recover.
I could then release the clutch/brake and ride for varying times, sometimes 5 minutes or less, others 30 minutes or more.

If I did not push in the clutch/brake, the engine would die. I would then restart the engine and ride for varying times.

Does this still sound like a belt problem?

 

[Molerj]

Nope, doesn't sound like a belt problem. Now, I am thinking more on the lines of the
seat switch. If the switch is failing the engine will die (thinking you are off the seat).
Now, when you step on the clutch it is the same as when you set the brake & get off
of the tractor. The engine keeps running. I know it sounds odd, but I was working on my
neigbors tractor that had similar symptoms. His (Cub) was cutting out while he was cutting
grass & he would mess with the electric PTO switch & it would recover, only to do it again
later. He replaced the PTO switch only to have the problem remain. I jumped out the seat
switch & that problem disappeared. See if you can jump out your seat switch before you
go out and buy a new one. At any rate, it seems as though it is one of the safety
switches that is causing your problems. Let us know what you find.

 

[kubmech]

Yeah Ron, I was just thinking the same thing. Another twist to it would be when pushing in on the clutch/brake he is applying more pressure to the seat switch, re-engaging it and allowing the engine to continue to run. Some model tractors have a weight adjustment on the seat. I remember we had a problem with one of those, the mechanic that was checking out the problem could not get the machine to die. I eventually went out to the cust's location to see if we could get to the bottom of it by watching him run the machine. Sure enough it would cut out on him. That's when it hit me, this guy weighed all of 125 pounds. The guy that was checking it out was 290 plus. After a little adjustment, problem solved.

 

[heehaw]

when it starts to die, pull the choke out, if it runs better, not good, but better, with the choke out, you have a fuel problem.
heehaw