Hello this is pretaining to a 12 HP Briggs and Stratton engine in a Noma/Murray riding mower with 4 wheel steering from 1989 sold under the AMF/ Agway brand.
Engine 281707 type : 0425-01 Code 89103031 Cast iron bore.
Issue: When riding it randomly starts to stall out as if you were mowing and started to get up from the seat. At first I felt it was that I was bouncing around lifting enough off the seat to trigger the safety cut off. But I tied those wires together and that was not the issue.
The issue is worse when the PTO is on and mowing. There is more of desire to stall but it catches itself. I had removed the needle from the bowl (see hisorty) and maybe just do not have the correct position and have no experience in carburetor adjustments.
Recent History- THE FIRE....dum dum daaaa-- recently a mouse built a nest under the shroud which caught fire and melted the sparkplug wire and there wre some quick rapid pops /backfires and I shut down. Thinking the engine blew up do the smoke I let it all cool down and then I was able to run it two more times. Then it just failed to start. As I was examining the issue Mr mouse dropped out from under the shroud. I found the nest around the wire and cleaned that up. I bought a new magneto and installed it with the shim card provided in box. (the paper instruction card was the shim)
I also replaced the plug with a briggs gold plated spark plug gapped at 3 (I forget, .3 or .03) at the time it was confirmed the factory gap was correct.
Other History: I do not have a garage. I have to store it on a pad out side with a lawn mower cover.
This mower has had some weather abuse. The cover would occassional blow off in a rain storm and it seems water gets into the engine all the way to the oil. The hood on the tractor has vents in most of the top. I do not know if water can get to the interior from the fly wheel so suspect it goes down the carburetor from the air cleaner. I say it seem water gets in since when I see it in the oil it never smells like gas. I usally just drain the carb bowl and oil, crank a few times with the plug out and then I am back in business.
The fly wheel has rust on it. Sometimes it is hard to turn over, not spinning fast enough at first. The battery was name brand replaced last year and expensive. (not a walmart lawn battery) . Turns over smooth and fast with plug removed.
The carburetor has beem removed and cleaned with carb cleaner. But if you do not use the shut off it seems gas will leak into the engine and then the oil. A mower repair shop said it was not worth trying to fix since the needle was not the issue but I guess the seat. They just said to be sure you keep the fuel shut off closed.
Engine back fire- I have a back fire when the mower is hot and I shut down at full speed. If I throttle all the way down before turning off or turn the fuel off and wait until a studder there will nto be the LOUD backfire.
So as long as I keep it out of the rain and the fuel shut off during longer periods it was running fine
BEFORE THE FIRE-
Before the fire I di not have this current issue. However I did have the cover blow off and it was not starting after the oil change so I drained the bowl on the carb. This fixed the issue however the nut that holds the bowl on was chewed up by someone before I got her and it got to that point were I could not get it off. In a hurry, I just removed the needle to drain the bad gas or water out. And she started right up.
I am guessing I did not get the needle back in the same position or it is not related.
All I do is play with the needle. When warm I turn the needle until I hear hesitation at idle and then back it so it sound like it is running smooth.
You can mow at any gear speed and this will happen. It is random and seems to be there without the PTO on but less than with the PTO on. It is most noticed when making a turn, pulling fast off the clutch in forward and reverse when there is more load.
It did not do this before the fire. WHen I had the bowl off I opened the fuel shut off and fuel did flow but I was not sure if the rate was as much as it should be. I have to still get a new fuel fiter to be sure but just befor the mouse fire it did not do this so do not think it is the filter. There is also a screen in the tank so do not think much debries gets past.
If anything the filter slows flow due to it having to fit into the lines .
OK there you have it. I only mention the other history and problems in case it helps for the topic of the hesitation.
In summary, when driving the tractor it randomly starts to loose power similar to if you sat up while mowing and the safety cut off was triggered.
Thanks
Engine 281707 type : 0425-01 Code 89103031 Cast iron bore.
Issue: When riding it randomly starts to stall out as if you were mowing and started to get up from the seat. At first I felt it was that I was bouncing around lifting enough off the seat to trigger the safety cut off. But I tied those wires together and that was not the issue.
The issue is worse when the PTO is on and mowing. There is more of desire to stall but it catches itself. I had removed the needle from the bowl (see hisorty) and maybe just do not have the correct position and have no experience in carburetor adjustments.
Recent History- THE FIRE....dum dum daaaa-- recently a mouse built a nest under the shroud which caught fire and melted the sparkplug wire and there wre some quick rapid pops /backfires and I shut down. Thinking the engine blew up do the smoke I let it all cool down and then I was able to run it two more times. Then it just failed to start. As I was examining the issue Mr mouse dropped out from under the shroud. I found the nest around the wire and cleaned that up. I bought a new magneto and installed it with the shim card provided in box. (the paper instruction card was the shim)
I also replaced the plug with a briggs gold plated spark plug gapped at 3 (I forget, .3 or .03) at the time it was confirmed the factory gap was correct.
Other History: I do not have a garage. I have to store it on a pad out side with a lawn mower cover.
This mower has had some weather abuse. The cover would occassional blow off in a rain storm and it seems water gets into the engine all the way to the oil. The hood on the tractor has vents in most of the top. I do not know if water can get to the interior from the fly wheel so suspect it goes down the carburetor from the air cleaner. I say it seem water gets in since when I see it in the oil it never smells like gas. I usally just drain the carb bowl and oil, crank a few times with the plug out and then I am back in business.
The fly wheel has rust on it. Sometimes it is hard to turn over, not spinning fast enough at first. The battery was name brand replaced last year and expensive. (not a walmart lawn battery) . Turns over smooth and fast with plug removed.
The carburetor has beem removed and cleaned with carb cleaner. But if you do not use the shut off it seems gas will leak into the engine and then the oil. A mower repair shop said it was not worth trying to fix since the needle was not the issue but I guess the seat. They just said to be sure you keep the fuel shut off closed.
Engine back fire- I have a back fire when the mower is hot and I shut down at full speed. If I throttle all the way down before turning off or turn the fuel off and wait until a studder there will nto be the LOUD backfire.
So as long as I keep it out of the rain and the fuel shut off during longer periods it was running fine
BEFORE THE FIRE-
Before the fire I di not have this current issue. However I did have the cover blow off and it was not starting after the oil change so I drained the bowl on the carb. This fixed the issue however the nut that holds the bowl on was chewed up by someone before I got her and it got to that point were I could not get it off. In a hurry, I just removed the needle to drain the bad gas or water out. And she started right up.
I am guessing I did not get the needle back in the same position or it is not related.
All I do is play with the needle. When warm I turn the needle until I hear hesitation at idle and then back it so it sound like it is running smooth.
You can mow at any gear speed and this will happen. It is random and seems to be there without the PTO on but less than with the PTO on. It is most noticed when making a turn, pulling fast off the clutch in forward and reverse when there is more load.
It did not do this before the fire. WHen I had the bowl off I opened the fuel shut off and fuel did flow but I was not sure if the rate was as much as it should be. I have to still get a new fuel fiter to be sure but just befor the mouse fire it did not do this so do not think it is the filter. There is also a screen in the tank so do not think much debries gets past.
If anything the filter slows flow due to it having to fit into the lines .
OK there you have it. I only mention the other history and problems in case it helps for the topic of the hesitation.
In summary, when driving the tractor it randomly starts to loose power similar to if you sat up while mowing and the safety cut off was triggered.
Thanks