Not sure what is wrong with this mower-won't start, smoke coming out of carb

I have a Craftsman 6.75 rear drive self propel mower that a friend of mine gave me a few months back.

I used it most of the summer. The self propel was acting weird so I replaced the belt, I found out after taking the blade off that the lower bearing support on the blade end of the drive was missing all of the ball bearings (looked like it had been for some time no idea why), but that part is no longer available so I just put it back together with the new belt. It worked alright, threw the belt on the rear drive end a couple times but no other issues.

About a month ago I got it out to mow and noticed when I started it up it was making some kind of clanging noise, and it threw the belt. I fixed the belt, started it again and it again threw the belt and was still making the noise so I turned it up on its side to see what was going on.

When I went to take the blade off I noticed the blade bolt wasn't tight, and then after removing the blade I found out the blade adapter was cracked almost all the way down one side. I have no idea how this happened as I don't recall hitting anything and everything with it was fine when I put it back in the shed the last time I used it (I keep it locked up).

I took everything apart and ordered a new blade adapter off the Sears Parts website. I noticed when it came in it wasn't exactly the same as the old one but it seemed to fit OK and the blade cleared the deck and everything else fine so I figured it wasn't an issue.

Well, now it won't start and I'm not even sure what it's doing. When you pull it, it sounds like it tries to start and a couple puffs of black smoke come out of the muffler, then it kind of kicks back and smoke comes out of the carburetor (I know that's not good). It's also making a weird sort of knocking sound when you pull it and it turns over (not really sure how to describe it, sounds like something is hitting something else). What is it doing and why is smoke coming out of the carb?

 

Sorta sounds like your flywheel key might be sheared, which probably happened at the same time your blade adapter got broken but just now has shifted far enough to make it mess up. The noise... you can't see the blade hitting anywhere? If not, is the engine still tight on the frame? Is the blade able to wiggle on the shaft?

 

You also have to replace the Ball Bearing that was destroyed.

Sears may say it's no longer available but they used mostly standary size ball bearings and I'm sure that if you do the research, you'll find an equivalent.

If you still have the race and the inside diameter, most fully equipped auto parts stores will be able to sell you a match.

Do you have an Owners Manual for that machine ?

 

They key looked like it was fine, I didn't have any problems removing or installing any of the parts on the shaft. I also spun the blade a few times and it doesn't look like it's hitting anything. I'll have to check to see if it wiggles or not, and check the engine. Everything looks like it's OK though.

As for the bearing- well, it never caused any issues before. I know it's supposed to be there, but it looks like the bearings have been gone for a loooong time. It kinda looks like the inner race is part of the lower side of the pulley that the self propel belt rides on, and I can't even see how you could press out the outer race. I guess I'll have to look at it again.

 

Did you remove the flywheel to check the key, if you didn't it can be sheared below the end and will look ok from above. Have a good one. Geo

 

I didn't even know these things actually had a flywheel. I had everything off for the self propel but didn't see anything that looked like a flywheel. I'll have to take it apart again and check. Going on vacation tomorrow so it will have to wait a week I guess.

 

The flywheel is the thing on top that spins when you pull the starter rope you have to remove the engine shroud to get to it. To remove the nut that holds the flywheel on remove the spark plug and fill the cylinder with small rope like starter rope leaving a little hanging out when you start removing the nut holding the flywheel the engine will try to compress the rope and lock so you can remove the nut. Have a good one. Geo