QuestionQUESTION: Hi, I have a craftsman 5.5 hp push mower that is ten years old. Model # 917.387160 From what I described to people, they are telling me it's the flywheel key. The starter recoils back and it back fires a little bit too. It does start though but only keeps running if I maintain the primer. Once I stop pumping the primer, it stalls. However, when I took the mower apart, when I got to the flywheel key, it doesn't appear to be damaged. It looks to be in good shape. Is it possible that the flywheel key is damaged on the bottom, or is the common damage to a flywheel key on the top of the bolt itself? If it's not the flywheel key, I would assume it's the carb? Thanks.
ANSWER: Hello Larry:
Sorry for the Delay. This Question was Located in the Question Pool. Since you have Checked the Flywheel Key; Check the Crankcase Oil. Make Sure it is Not Overfilled. Check the Mower Blade and Make Sure it is Tight. If the Blade is Loose or the Crankcase is Overfilled you will have the Kick Back you Described. For the Running Problem, Even though the Carburetor Looks Clean, the Internal Passages May be Restricted with Varnish that Gas Causes to Build Up over Time. I Suggest you Make Sure the Gas is Free Flowing to the Carburetor Inlet Port. If the Gas is Free Flowing to the Inlet Port, then **Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl (if Applicable), Float Pin (if Applicable), Float (if Applicable) and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required.** Is the Coil/Magneto Gapped to .020in from the Flywheel? If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Thanks John. I now realize that I may not have gotten down far enough to the actual flywheel key. I'll explain. I took off the pull starter, the gas tank, the mower cover. This exposed the flywheel, with the flywheel bowl attached at the top. I then take off the flywheel nut, which allows me to remove the flywheel bowl. Is the bolt that the flywheel nut is screwed onto the actual flywheel key? Because I thought the flywheel key is actually rectangular in shape? Do I have to remove the flywheel itself to see the flywheel key?? I remember hitting a big rock a while ago which made the engine run weaker but it still ran. That was a while ago. The mower has been sitting a while because I have a rider too. So I should think the carb has build up too. Thanks for all of your friendly advice. Whatever more you can tell me is appreciated. Thanks, Larry
AnswerHello Again Larry:
The Rock Damaged the Flywheel Key and that is the Reason for the Slight Power Loss. Every Time you Shut Off the Engine, the Key was damaged a Small Bit More Until Now the Engine Will Not Start. ***Remove the Blower Housing (metal engine cover). Remove the Flywheel Nut or Starter Cup (Depends on the Model). Now Attach a Steering Wheel Puller to the Flywheel Using the Threaded Holes in the Flywheel. Tighten the Puller. Now Hit the Puller with a Hammer. Repeat this Procedure Until the Flywheel Pops Up or can be Lifted Off the Crankshaft. On Some Models you Can Not Use a Puller and Must Use a Pry Bar and a Pipe Cap that is Slightly Larger than the Crankshaft. Place the Pipe Cap Over the Crankshaft to Protect it. Place the Pry Bar Under the Thick Section of the Flywheel and Pull Up Against the Flywheel. **BE CAREFUL DO NOT PUT A HOLE IN THE BLOCK UNDER THE FLYWHEEL** Now Hit the Pipe Cap that is on the Crankshaft (covered with the Pipe Cap). Repeat the Procedure Until the Flywheel can be Lifted Off the Crankshaft. *** If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
