Tecumseh 3.8hp on Eager-1 not starting

[brianz]

Hello forum members,

Engine info:
I have a Tecumseh model 143-943814-4061k engine on a Craftsman Eager-1 push mower model 944-364160 that wont start.

What happened:
Last week 3/4 of the way through cutting the lawn the mower stopped running. It made a muffled pop/backfire sound and just stopped. It was on level ground, hadnt hit anything, minimal amount of grass being cut. Tried to restart, but on pulling the cord it makes a wheezing sound thats coming from the crank case breather tube. It sounds like a goose gasping for air through a straw. The pull cord also feels a bit odd, like the piston is sticking or something.

I have had the mower make a single small pop of an ignition a couple of times after many very hard attempts at pulling the starter cord. It hasnt started properly yet.


What I tried to fix:
So I checked for spark by grounding the plug to the head and pulling the starter cord, and its strong and consistent. I checked compression with my finder on the spark plug hole and it feels strong. I checked the carb, and found the float has liquid inside so I replaced the float, needle, seat, and gaskets for the bowl/bottom jet.

Nothing. So I pulled the flywheel and checked the key. Its absolutely perfect. So I pulled the head. For a 20 year old mower, not bad. No pitting, moderate carbon build up that mostly came off by carb cleaner. Both valves rotate freely, not sure if thats normal but they seem to seat properly. Though when turning the engine over there was a couple large drops oil on each stroke that got pushed up by the piston. Not sure if this is normal? Seems like worn rings letting oil through.

Still wont start. It still makes the wheezing sound from the crank breather hose, and the engine feels lumpy when the starter cord is pulled.

Any ideas?

 

[possum]

Does it have gas to the cylinder? Put a small shot in the cylinder and try it. Do so away from building and outside.

 

[brianz]

Does it have gas to the cylinder? Put a small shot in the cylinder and try it. Do so away from building and outside.

Putting a spray of quick start into the air intake of the carb results in the same single pop but no ignition. the engine does a partial revolution with the pop, but theres no proper ignition and power being produced.

i didnt spray direct into the combustion chamber as i was able to get ignition from the air intake off the carb.

Is this engine blown? What is it doing?

 

[Lairdslawnmowers]

You can also check the key on the blade adapter. A lot of mowers use the blade for balance and if the keyway is off there it can cause timing issue the same as the flywheel key.

 

[brianz]

You can also check the key on the blade adapter. A lot of mowers use the blade for balance and if the keyway is off there it can cause timing issue the same as the flywheel key.

Good idea. I somehow haven't checked the blade key. I will check first thing tomorrow.

 

[brianz]

Good idea. I somehow haven't checked the blade key. I will check first thing tomorrow.

I pulled off the blade and blade key, and the key looks perfect. It came off no problem. Everything on this mower looks clean, nothing is corroded together, it all come apart no problem, but it wont start.
With the blade off, I rotated the crankshaft by hand, and it feels like its sticking and unsticking about every 1/4 turn.

Is this what a bent crankshaft acts like? I'm pretty confident in the troubleshooting done so far, and the only thing I have not previously worked with is a bent crankshaft. Am I going down the right path here?

 

[brianz]

I had a small engine repair guy look at it. The governor is not working correctly. Moving the governor arm back and forth just a little gets it started, and can barely keep it running if you can move the governor arm quick enough the right direction before the engine chokes out.

The repair guy couldn't fix it, so no charge. Can a governor just be removed, or is there some procedures i can try to fix/free it up?