Have you checked that it has spark when it shuts off? Have you checked that the carb solenoid is operating OK? IF there is no spark, may be the coil, they are the one B&S weak coil.

Answer back and we will go from there.

Walt Conner

something does not add up. The tractor is 2006, but the opposed engine was no longer produced after 2002.

You have already listed some problems with your engine.
1. the engine stops and will not restart for multiple days
2. the dip stick has a fuel smell
3. one of the intake valves does not have clearance

each of the items mentioned needs to be addressed.
Start with Walt's suggestion. The engine manual has specific instructions to test ignition and the fuel solenoid if equipped.

If there is no valve clearance, there is more work required than simply grinding the valve stems. Most likely the valve face is worn or there is a problem with the valve seat. This needs to be investigated and corrected.

The fuel system should be addressed next. Fuel can enter the crankcase from either a leaking carburetor needle valve or the fuel pump pulse line due to a failed diaphram. Check the fuel line from the fuel tank for blockage. If the fuel line is cracked, the fuel pump may draw air instead of fuel. To help with troubleshoots, try priming the carburetor after the engine quits.

First, Thanks for the replies. I very much appreciate the help.

I bought this tractor used two months ago; 1st tractor I've owned. I was told by the previous owner that it was a 2006. He may not have been truthful. I also do not have a manual for the tractor.

I don't believe this engine has a fuel solenoid. I don't see any electrical wires leading to the carb and I couldn't find the solenoid on the parts schematic.

I ran the tractor today and it did not quit, today was the first day that it didn't stall out. It did have a significant muffled/sputter sound, almost like a mis-fire. This sputter sound happened every 1-2 seconds and started after about 30 minutes of running. Typically the sputter leads to the engine stopping. I did not check for spark since it didn't fully quit, although I probably should have still checked. Ignition coil makes sense. Looking back, I may be flooding the engine trying to restart after it quits. Could this cause the fuel smell in the oil and preventing restart for days?

I think I need professional help with the valve problem. That sounds beyond my skill level.

Fuel lines looked good. I had replaced the fuel pump diaphragm a month ago. I'd like to believe the needle valve is ok since it is new, but I guess I can't guarantee that. I will try priming the carb and checking for spark next time the engine quits. Sorry, I'm all over the map with this.

Posting the Sears 917.xxxxxx number would allow the rest of us to see what you have.

After the tractor has sat for a few days, then check the oil level to see if it has mysteriously risen and smells like gasoline.

The tractor model number is 917.271832.

Is there a difference between a coil and a magneto?

Thanks

Essentially, an IGNITION COIL (by that name) needs an external electrical power source and a controller of some sort in order to function as a spark producer.
Whereas a MAGNETO is a completely self contained spark producer that needs no external power supply to operate with.
Magnetos produce their own power supply that is independent of the vehicle's or apparatus' other electrical system.
However, it is traditionally accepted to refer to the ignition spark producer of an engine as IGNITION COIL or COIL in colloquial speak.
Briggs themselves call the part an ARMATURE in their literature.
The item in your engine is specifically of the Magnetron type (meaning that it has some basic electronics in it to control spark timing).
The correct Briggs part number that you need is 394891.
And make sure you mount the new one with the exact orientation as the old one cause if you mount it backward it will not work.

OM is here-
http://www.managemyhome.com/mmh/lis_pdf/OWNM/L0105086.pdf

The tractor & engine#'s do match up.
Date on the OM is 4-27-2001.

The carb does NOT have a fuel solenoid, so that can be dismissed.

Actually, the model and type numbers I found are an exact match to what the OM states in in there.
What DOES NOT match up is the claim of it being a 2006 year model tractor.
And as Bill stated, the publication date of the Craftsman manual is exactly what he said he found too.

OP - here's a link to your machine's owner's manual:

Here is a link that might be useful: 917.271832 tractor

Wow! I got scammed. Thanks for all the help everyone. Lesson learned.

I will post back with status after I fire up the tractor again. Should be this weekend.

Following back up. The tractor has not been stalling or sputtering. Not sure what the difference is. One thing to note is the days have gotten cooler. Could this be a factor with the magneto?

Sometimes they can get heat sensitive and fail when hot.

BTW- Have you cleaned the cooling fins on the engine?
That's a bit of normal maintenance that gets overlooked by most.

Kevin, the magnetos on these Briggs Opp Twins do have a dubious track record but my own personal experience with the one Opp Twin engine I own is a little different from what you are seeing.
My engine runs well in hot weather.............until you cut it off and then try to restart it without allowing time for it to cool down. During the time the engine is still "heat soaked" no spark is delivered to the plugs. Give the engine a half hour to cool (or 10 minutes with a squirrel cage fan directed on the engine) and spark returns and engine runs. My theory on this is that so long as the engine fan is turning, the magneto is essentially one of the coolest components since it is located right next to the fan.
In the case of my engine losing spark, I believe it is because the heat soaked engine mass radiates sufficient heat after turning the engine off that the magneto warms to the point that the electronic parts inside the mag fail to act properly and thereby don't allow a spark to be delivered to the plugs.
I have not experienced any erratic spark or misfire so long as the engine is kept running.
With those thoughts in mind, your slight skipping or flutter sound in the exhaust might be due to a lean burn condition caused by the fuel system design in conjunction with hotter operating temperatures (ambient air temp being just one factor).
Lean burn or lean mixture means that the air to fuel ratio is "lean" regarding the volume of fuel present in the intake stream fed to the engine.
Lean conditions can be caused by a few different things, some of which are basic design factors such as the size of the main fuel jets in the carburetor.
Other factors that can result in a lean condition may be due to the "health" of the engine in general and how that health may affect the air/fuel ratio.
One of those health issues is whether the fuel pump can adequately keep pace with the rate of fuel consumption. If for some reason a fuel pump can't maintain sufficient fuel volume to keep the carb bowl filled, a lean condition will develop. Since your fuel pump diaphragm has been replaced we must presume it is delivering enough fuel.
Another factor that can cause a lean condition is the engine cooling system duct work that carries air from the fan to be directed over the cylinders and cylinder heads.
If there is any kind of blockage anywhere in the air ducting sheet metal shrouding the engine.......air flow will be reduced across the hot surfaces and the surfaces will become even hotter, which will result in a lean condition. And because a lean condition actually burns hotter too, extreme air flow blockage will turn into a vicious cycle that might ultimately end in engine failure with catastrophic damage to cylinders, pistons and other parts.
Somewhere below the extreme zone an engine can develop the "lean burn flutters".
You would do well to remove all the sheet metal ducting from the engine and clean the cooling fins of the cylinders and cylinder heads.
All too often we read in this forum where engines have been trashed because because mice built nests or food caches inside the cooling ducts and the engine succumbs to severe overheat without any forewarning to the owner.
A word to the wise is "Clean your air ducts prior to the onset of the annual use cycle".
Even if you don't have rodent activity there might be dust and mowing debris lodged in places that will tend to reduce cooling.

bill, you beat me to the punch there.
But I was doing one of my periodic "long winded posts" on this quiet morning (with a big cup of coffee) while I get ready to face the day.
Have a good one.

Is there an inexpensive testing device that you guys would recommend for checking proper performance of the magneto/ignition coil/coil?

To my knowledge, the best way to test the magneto on Briggs engines is to use the Briggs ignition tester part # 19368.
This high tech device allows you to observe the ignition spark while still delivering the spark to the spark plug.
With this device you can watch the spark while the engine is running (or cranking).