sears

[Robert12345]

i have a sears 12 hp tractor, it will run but is out of time spins with plug out but struggles with plug in, i looked at vertical shaft keyway and it looks like it hasnt moved, is there another keyway and is there another way it can be out of time? it will run with a shof ether?

 

[timcasbolt]

I haven't heard of more than one keyway, but I have heard of points out of adjustment affecting the timing.

 

[wore out]

i have a sears 12 hp tractor, it will run but is out of time spins with plug out but struggles with plug in, i looked at vertical shaft keyway and it looks like it hasnt moved, is there another keyway and is there another way it can be out of time? it will run with a shof ether?

For a better chance of getting help you may as well post the model number of the tractor and the make and model of the engine (typically on a "tag " or stamped onto the tin" shrouding over the flywheel).

 

[Robert12345]

.I WILL GET MORE ENGINE INFO. ANYONE KNOW WHERE POINTS ARE ON THESE ENGINES?. DIDNT SEE ANY THING LIKE POINTD WHEN I PILLED COVER TO SEE KEYWAY

 

[J Hamilton]

.I WILL GET MORE ENGINE INFO. ANYONE KNOW WHERE POINTS ARE ON THESE ENGINES?. DIDNT SEE ANY THING LIKE POINTD WHEN I PILLED COVER TO SEE KEYWAY

Like wore out has stated, we will need to know what engine it has to be able to help you.

 

[kencombs]

i have a sears 12 hp tractor, it will run but is out of time spins with plug out but struggles with plug in, i looked at vertical shaft keyway and it looks like it hasnt moved, is there another keyway and is there another way it can be out of time? it will run with a shof ether?

If the engine has a compression release, it may not be working. Common issue with some engines. More engine info will help.

 

[Robert12345]

i have more information om my craftsman 17.5 hp briggs engine. the mower is a model 33748 bought it is 14 yrs old, as stated it turns over very hard as if out of time, with a little ether it will start and run., jumpered battery, etc, i feel if its the starter it would turn over slowly instesd of strugglimg and then turn over one revolution, looked at key way at top of vertical cam shaft it is inline, is there another keyway or some other way it could be out of time.?i . thanks for any help

 

[Robert12345]

also if it is the points what do i have to do to get at them?

 

[timcasbolt]

That type of engine may not have points.

 

[timcasbolt]

An owner's manual for your tractor might be helpful.

 

[Rodney51Cub]

That model number does not come up on the Briggs web site. The model number is usually 6 digits on the newer engines. The model, type, code and serial number is usually stamped into the valve cover or on a tag on the fan shroud. Also if it is a newer engine it will not have points. Just a guess would be valves out of adjustment. If you find model, type and code numbers I can find engine info for you.

 

[Jim.ME]

An owner's manual for your tractor might be helpful.

I agree with Tim, the Sears owners manuals often have some engine info.

Somewhere on the engine there should be a tag (or it may be stamped in a housing) with the engine model etc. You need to find that and use the numbers from it to ID the engine, not the Sears/Craftsman mower model number. With those numbers you might find a manual on line. With the complete Sears/Craftsman mower number a search might turn up more info on the engine.

 

[T.R.K.]

If it is a 17.5 horsepower, likely it is a vertical shaft, overhead valve engine. The first thing I would check is the valve adjustment. Set the valves to .004 for intake and exhaust and see what it does then.

It is probably stalling on the compression stroke. I'm guessing it turns about a revolution and a half, then stalls again.

There is also the possiblilty that the compression release on the cam is bad, but if it is 14 years old, that would make it a 2010 and before Briggs went to the camshaft that had all the compression release problems.

If it is the engine I think it is, the engine model, type and code numbers should be either stamped on an aluminum tag on the cover by the flywheel or stamped on the valve cover.

 

[Robert12345]

If it is a 17.5 horsepower, likely it is a vertical shaft, overhead valve engine. The first thing I would check is the valve adjustment. Set the valves to .004 for intake and exhaust and see what it does then.

It is probably stalling on the compression stroke. I'm guessing it turns about a revolution and a half, then stalls again.

There is also the possiblilty that the compression release on the cam is bad, but if it is 14 years old, that would make it a 2010 and before Briggs went to the camshaft that had all the compression release problems.

If it is the engine I think it is, the engine model, type and code numbers should be either stamped on an aluminum tag on the cover by the flywheel or stamped on the valve cover.

IT IS STALLING ON THE COMPRESSSION STROKE, WHAT DO I HAVE TO TAKE OFF TO GET TO THE VALVES, I DO HAVE A MANUAL THAT CAME WITH IT , DO YOU USE AN FEELER GAUGE LIKE THE OLD ENGINES AND I ASSUME THE SPACE BETWEEN THE LIFTER AND THE VALVE STEM WOULD BE MUCH WIDER THAN .004. IF I DONT HAVE TO DIG TOO DEEP IN THE ENGINE I MIGHT GIVE ADJUSTING A TRY THANKS FOR YOUR TIME ANY GEN. INFO WOULD BE APPRECIATED FOR ME TO MAKE A DECISION TO TRY OR JUNK IT.

 

[Robert12345]

IF IT HAS A COMPRESSION RELEASE WILL THAT WHAT IT IS CALLED IN THE PARTS MANUAL THAT CAME WITH IT?

 

[Rodney51Cub]

As T.R.K. said, if it is a 17.5 horsepower, likely it is a vertical shaft, overhead valve engine. The first thing I would check is the valve adjustment. Set the valves to .004 for intake and exhaust and see what it does then.

All you do is remove the valve cover, set the engine to Top Dead Center on the compression stroke and set the clearance between the rocker arm and valve stem to .004. Yes, a lot of Briggs engines are set that close. It would still be good to get the model, type and code to verify what engine you have.

 

[kencombs]

IT IS STALLING ON THE COMPRESSSION STROKE, WHAT DO I HAVE TO TAKE OFF TO GET TO THE VALVES, I DO HAVE A MANUAL THAT CAME WITH IT , DO YOU USE AN FEELER GAUGE LIKE THE OLD ENGINES AND I ASSUME THE SPACE BETWEEN THE LIFTER AND THE VALVE STEM WOULD BE MUCH WIDER THAN .004. IF I DONT HAVE TO DIG TOO DEEP IN THE ENGINE I MIGHT GIVE ADJUSTING A TRY THANKS FOR YOUR TIME ANY GEN. INFO WOULD BE APPRECIATED FOR ME TO MAKE A DECISION TO TRY OR JUNK IT.

There is a specific method to set the valve lash. On 'most' B&S OHV engines the piston must be 1/4" down the bore before TDC to set the clearance to .004 between the rocker arm and valve stem. .But check your manual. The problem usually happens when the clearance is too tight. Just remove the spark plug and valve covers to do this.

 

[timcasbolt]

Just found this on you tube:

How to Adjust Valve Lash & on the Briggs & Stratton 17.5hp OHV Engine - Craftsman Lt Lawn Tractors​

Sorry: