I HAVE A CRAFTSMAN 7HP SELF- PROPELLED ,MY PROB. IS THAT I WAS CUTTING GRASS FOR AWHILE AND ALL OF A SUDDEN MY MOWER JUST LOST POWER AND TURNED OFF.NOW IT WON'T START .I THINK IT COULD BE THE MAGNETO (ANY SUGGESTIONS).THE MOWER IS ABOUT 2 YRS OLD

 

Is the oil to the full mark? Didn't make any noises when it did this did it? (just trying to rule out a seized engine) Try a new spark plug just in case, but take the plug out and put it back in the boot, and ground it to the metal head and turn the engine over and watch for a strong spark.. (really takes two people to do it)

 

V8DRIVER, I CHECKED THE OIL LEVEL 1ST ,THEN I WENT TO TEST IF THERE WAS A SPARK ,BUT NO LUCK ,DO YOU KNOW WHAT ELSE COULD CAUSE TO LOOSE POWER ALL OF A SUDDEN.IT DIDN'T MAKE ANY NOISE.

 

First, take the caps lock off! There is no need to SHOUT.

Did you hit anything while mowing? Shearing the flywheel key could cause the engine to not run. This is pretty cheap and easy to fix.

If you did not hit anything my next guess is bad fuel and a clogged carb. If that's the case cleaning the carb and flushing the fuel tank should take care of it.

Did you get the spark that v8driver mentioned?

 

NAVYDAD,

Check your gas cap vent. It may be clogged.

Dave237

 

If as you say, you checked and there is no spark, then that is your problem and could possibly be the magneto. How did you check for spark, by holding the plug attached to the wire against the engine? Have you tried a new spark plug? However, you described the engine as "losing power". Did you mean that it gradually had less power and speed, or did it suddenly cease running?

 

THANK YOU ALL FOR THE INFO,thiggy I TRIED A NEW PLUG BUT NO SPARK,YES WHEN IT TURNED OFF IT JUST GRADUALLY SLOW DOWN AND STOPPED. THE ONLY THING I HAVEN'T CHECKED IS THE FLYWHEEL KEY& I DIDN'T HIT ANYTHING IT JUST PUZZLED ME THAT IT STOPPED ON 2INCH HIGH GRASS.WHEN I TESTED FOR SPARK I HAD IT NEXT TO THE ENGINE I HAVEN'T TAKEN THE CARB OFF CAUSE I THOUGHT IT WOULD BE ELECTRICAL .BAD GUESSING ON MY PART.THANK YOU ALL AGAIN FOR THE HELP ,I AM GOING CHECK THE CARB,CHECK FLYWHEEL KEY,I,LL LET YOU ALL KNOW HOW IT TURNS OUT.

 

The spark plug must touch the engine when checking for spark so that you complete the required circuit (ground). If you indeed have no spark there are two areas that could be to blame (other than the ignition coil itself). The first is the brake cable and it must have a full pull of the brake assembly in order to disengage the kill circuit and the second is the coil ground (kill) wire could have a bare spot on the insulation and thus shorting out the coil. If these two areas are good then it's time to replace the coil.

 

I would suggest that you not worry about the carburetor till you resolve the 'no spark' situation.

 

well guys i took my lawnmower apart ,i found out that i did indeed have a spark from grounding the sparkplug i got zapped but i got it.i took the top part off ,but i can't get to the flywheel key slot part .i think i need a flywheel puller.i notice that the flywheel key was not aligned to the flywheel it was alittle to one side,would this cause my mower from starting.any suggestions as to what to try next.

 

Yep, a flywheel puller will be required to remove the flywheel without damaging it. Just purchase a new key at the same time you get the puller. Replace the key, button it up and you should be 'good to go'.

 

thanks thiggy ibought a puller and replaced the fly wheel key but my mower still won't start ,any other steps to take

 

Does the engine have any compression at all?

 

cheese,i don't have a tool to check compression on the mower is there a way that i can do to check for compression

 

This is no measure of compression but is a rough indication. Hold your finger over the spark plug hole while someone cranks the mower. Air pressure should be felt on the finger in the hole. Kinda hard to do as a one person test (glad no one watches me work sometimes :-) . If you are really concerned about compression you might try a local parts store for a loaner tool.

 

duigoose:i tried putting a paper towel in the sparkplug hole and it popped it out.let me ask you this question does a magneto often go bad even when it gives out spark?or as long as i see spark when grounding it.also when you get fuel into the camber the plug should be wet right?

 

duigoose:i tried putting a paper towel in the sparkplug hole and it popped it out.let me ask you this question does a magneto often go bad even when it gives out spark?or as long as i see spark when grounding it.also when you get fuel into the camber the plug should be wet right?





GOD BLESS

 

Dad, post back with the engines' as well as the chassis' ID numbers. This will help us better help you if we know which engine you have and on which frame it sets. Initially though, I'm still not convinced you have sufficient ignition. Go to your local Briggs dealer and buy, from them, part number 19368. This is an in-line spark tester and is the best means to check for sufficient spark. If you do have sufficient spark and you know the flywheel key is not sheared (again) (it is critical that the flywheel nut is torqued to specs) then I'd be concerned that you may have compression/vacuum issues within the combustion chamber. If this is suspected then you will want to remove the cylinder head and have a look at the condition of the cylinder wall and the valve train.

 

puey61: the number to my mower is 128602-0304 7hp craftsman ,sorry about that puey61.i cleaned the carb. today but no luck took it apart. it looks like it's leaning towards the guts of the mower,i have fuel & spark. delivery.my mower is fairly new so i am surprised it did this. no warranty on this mower,it's pretty powerful mower when running







GOD BLESS

 

Navydad & puey61;

..been following your troubles on this thread. Had the same problem with my "newly acquired" {very used, cheap} mower (Tecumseh engine, Sears # 143.016700) running well for about 5 minutes, then slowly loosing rpm and power until it just stopped. Before starting this bargain mower, I drained the gas & oil & replaced the plug after checking the gap. Knowing I had fresh gas in the tank and carb (loosened the bowl nut & re-tightened), and clean oil full in the reservoir, it was great to have it startup and begin work. The blade hardly had any wear, and I know the crank isn't bent.

So, what could be happening here? after the engine cooled down, I slowly hand turned the flywheel with the spark plug wire disconnected, (plug left in), only to hear a "whoosh" sound coming from the front. Took off the head, and found the cylinder walls badly scored and piston head very badly carbon'd up. I put a straight edge across the head, but it looked fine...but I can't eyeball 0.005" to 0.010" anyway, and there were no obvious cracks. The head gasket was in bad shape, and frankly, the head bolts weren't that tight to begin with. I then checked the paper air filter (which I should have done FIRST) and found it very dirty. I think this mower never had the air filter replaced, and this mower has suffered the consequences...think we're on the same page here Puey61??

Thanks for reading,
redshed

 

well guys ,thanks for your info, i finally found the problem to my slight headache ,after checking for spark,compression,fuel, it was the retaining nut to the intake valve that had worked it'self loose ,i retorqued the nut and it fired right up.thanks again






GOD BLESS