No-start Crapman

[JDgreen227]

Replaced the flywheel key on my step-mom's 6.25 hp Craftsman Tecumseh, reassembled it and put in fresh fuel and a new spark plug. Primed a few times, on the second it caught for a second and then died...now it will not fire at all. Compression is strong, New plug is properly gapped, new air filter, fresh fuel, and it's getting fuel. Flywheel brake (deadman control) works perfectly. It does seem to be a bit difficult to pull over, like the starter rope is hanging up, but it's a nearly new rope and not rubbing or fraying on anything. Yes, the starter pulls the correct number of turns with the new rope.

For the life of me I cannot understand why this (censored) thing will not start. Any ideas? Thanks.

 

[RobertBrown]

I know you said that it's getting fuel........
It's spring time and I'm guessing that the engine has been sitting all winter. I think you know where I'm going with this......It's not uncommon for fuel to leave residue in the carb jets after sitting for long periods.
That would be the most likely scenario. Not saying that's the problem, just saying it happens all the time.
B12 chemtool
Are you sure it was put up in running condition last fall?

 

[JDgreen227]

I know you said that it's getting fuel........
It's spring time and I'm guessing that the engine has been sitting all winter. I think you know where I'm going with this......It's not uncommon for fuel to leave residue in the carb jets after sitting for long periods.
That would be the most likely scenario. Not saying that's the problem, just saying it happens all the time.
B12 chemtool
Are you sure it was put up in running condition last fall?

Thanks, but it WAS running fine when my step mom hit the rock this spring...and I stored it for her last fall and the fuel was drained. You can prime a few times and the plug comes out wet with fuel and I have checked the entire carb, replaced the fuel line, made sure the float works properly and I KNOW the engine is getting fuel and it has a spark and the compression tests out to 76 psi with no oil in the cylinder. Specs for NEW Tec engines should read 80 psi. The only thing I can think of is that the crank is badly bent but I checked it for runout both atop the engine and below the deck and cannot find anything measurable. WEIRD.

THANKS again for your input.

 

[Canada_CT230]

Buy another new spark plug. Wouldn't be the first time that today's shoddy materials and workmanship delivered a dud plug.

Spend the $3 and eliminate that for sure. Otherwise, I agree with the build up of lacquer/varnish from the gas...even a small amount of gas that could have been left in there.

I had a small passage in the float bowl of my Honda water pump plug up and stop working....same thing. Worked fine in the fall and over the winter (after stored properly) it didn't run.

As a pilot and aircraft owner....aviation spark plugs are trashed if dropped on the floor. They can crack inside where you can't see and not work properly.

 

[General Lee]

I was gonna say the crank is probably bent from the rock strike, but it sounds like you looked into that. Other than that I got nothing....... On second thought......pour some sea foam in the carb and let it sit over night.

 

[RobertBrown]

Hit a rock? How did I miss that?
Did you recheck the fly wheel? When it did run, did you notice any excessive vibration?
Look at the coil and see if it was damaged when the flywheel jumped:confused3:

 

[JDgreen227]

Have tried 3 new plugs and they all spark fine when out of the engine...pushing primer forces fuel into the cylinder, carb has been taken apart and cleaned (last night) and found nothing wrong. Flywheel was off maybe 4 degrees when the key broke, but was still not touching the magneto and air gap was and still is set correctly.

Got spark, got fresh fuel, got strong compression, and it still won't even pop once or twice when I pull it over...and I have tried to pull it over at least 120 times. What I find strange is that it did almost start once in the very first few pulls I gave it, but since then, nothing.

Thanks all...if I find the cause I will let you know.

 

[jmurray01]

Now that is strange.

The only thing it possibly could be given that it is getting the three things an internal combustion needs (fuel, air, ignition) is the timing.

I know from experience that hitting a rock, or even a small stone can bend the flywheel in certain instances.

 

[murphy1244]

Try starter fluid and see what happens

 

[JDgreen227]

Now that is strange.

The only thing it possibly could be given that it is getting the three things an internal combustion needs (fuel, air, ignition) is the timing.

I know from experience that hitting a rock, or even a small stone can bend the flywheel in certain instances.

On a small rotary mower engine like this one, the flywheel is at the top of the crankshaft and held into place by a soft metal key which is designed to shear if the mower blade hits an object. The flywheel itself is almost impossible to damage unless you drop it once it is removed from the crankshaft. Timing is spot on with the new key I installed although it was a few degrees off when the key sheared originally. I am going to swap out the magneto with the one on my newer Yard Man pusher to see if that makes any difference. As for starting fluid...rather hard to spray it into the carb intake while pulling the starter rope and holding the handle at the same time. I could probably pull the plug and squirt some in and reinstall the plug and try that...still, seems to me if this mower wanted to start it would at least fire once in a while but it won't even pop once.