Small Engines (Lawn Mowers, etc.): Lawnmower starter problem, starter rope, screw type

Question
Michael, you were right on: flywheel key is sheared.  I was dubious because I didn't think that the lawnmower had fired any of the times that I pulled the starter.  Also, the guy who gave it to me didn't indicate that it stopped working suddenly after hitting something.  Moreover, the blade had no tell-tale sign of hitting something hard.  Well, all I had to do to test this hypothesis was to pull the starter with the spark plug out (that's a lot easier than getting that nut off the flywheel--I ended up needing to reinstall the blade and blocking it with a thick piece of wood to remove that nut).  Well, no kickback without the plug in, so that supported your diagnosis.  I got off the flywheel nut and saw the sheared key.  I don't have a puller, but since I keep working on mowers, I've determined that I need to get one. I'm not constantly working on small engines, but when I need to get the flywheel off, I don't want a hassle.  I'm a cheapskate, but I want one that will do the job right for the most models of lawnmowers.  Please tell me which of these three you recommend for me:

1.  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=66760&item=4348348660&rd=
Tecumseh part: Cost ~$20.

2. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4558417366&ca
"Universal" screw type puller: Cost ~$16.

3.  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50377&item=3983337872&rd=
"Universal" hammer type puller: Cost ~$9.

4.  A different one that you know of?

Thanks,
Scott

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Followup To
Question -
Hi Michael,

This is a Sears Eagle-1 walk behind mower with a Tecumseh engine.  The pull rope starter is the kind that has 2 metal tabs that come out and catch a bell shaped thing on top of the flywheel.  The problem is that when I pull on the starter rope to start the mower, I can pull it back all the way, but it rebounds with such force that it's dangerous.  A couple of times, the pull grip hit me with such force that it felt like I'd been hit with a hammer.  The mower also hasn't started.  

That's the summary.  I'll now go into detail, which may help you diagnose the problem.  A guy gave me this mower last year, saying that it had sat around a while, and would probably be fine with a tune-up.  I started working on it this weekend.  I took off the flywheel cover, gas tank, and carb to clean everything.  I then put on only the flywheel cover with the bolts just in far enough to hold it on.  I did this to check spark at the plug while I had things partially disassembled.  The starter was barely catching, so I determined that it needed replacement.  I had another Eagle-1 mower with a Tecumseh engine lying around for parts, so I tried to fit its starter, but it wouldn't fit the flywheel cover right, so I took the flywheel cover from the parts mower too, and put both on the new mower.  (Besides the non-matching of the starters, it's strange that though they apparently have the same or similar engines, the engines are mounted in opposite directions.)  When I finally finished everything else, I was ready to start it.  I always prime old mowers with starting fluid through the intake manifold or spark plug port.  I was wondering whether I'd have the same problem of the starter not catching, thus pointing to that bell thing on the flywheel as being the probable problem, but, instead, the starter caught, but after pulling back all the way, it quickly rebounded with such force as to yank the grip from my hand. I wondered if the mower was backfiring, that is, firing a time or two in the wrong direction, but I tried a few more times, and got the same result.  So, I decided that this starter was bad, and proceeded to replace it with the original starter and flywheel cover to see what would happen.  I don't know why the original starter didn't catch when I first had tried it without everything fully assembled when I was checking spark at the plug.  Well, now this starter was catching fine, but I got the same result as with the previous starter on every try.  Now, I don't believe that both starters have the same problem, so I'm wondering whether I did something wrong to cause this problem.  As far as I can see, there is only one way to mount the starter, so it can't be pulling in reverse.

Thanks for your help,
Scott


Answer -
Hi Scott,

I could almost guarantee that the flywheel key is sheared.  The timing would then be off.  The flywheel is located under the recoil/cooling shroud. It's bore is tapered and mates with the tapered crankshaft. The keyway in the flywheel and shaft keeps it from spinning on the shaft.  A nut secures it.  Use an impact wrench on the nut or a strap on the flywheel.  Don't put force on the cooling fins or they will break.  The recommended way to remove a flywheel is to use a puller.   An alternative, is to tap on the crankshaft top, with a brass hammer or use a punch tip on an air hammer.   The flywheel will need to be held up and supported or upward pressure applied with 2 large prybars. (A 2 person job.) Care is needed so the flywheel doesn't crack or bend.  Also be careful to not mushroom over the crankshaft top.  Replace the key.  Install the flywheel after cleaning the tapers and re-tighten the nut to 65 ft/lbs.
There is also the possibility of a bent or twisted crankshaft if the key was sheared due to a blade impact but usually the key just shears.  

Let me know how you make out.
Michael  

Answer
Hi Scott,

Good thinking, to test the problem with no spark in the picture.  

I would go with the universal puller, as you might be able to use it with other applications.  The Tecumseh puller would be best for Tecumseh only and the hammer type is...well... better than nothing when hitting the crankshaft, even with a brass hammer.

I'm glad you found the problem and will soon be up and running.

Best,
Michael