QuestionQUESTION: John,
I have a Craftsman 10" mini tiller, Model No 536.797500, with a 32.8cc 2 cycle engine. The engine runs and revs up fine, but the tines won't turn anymore. I took the gear case off the engine - the tines turn when I turn the drum manually. I opened the case and checked the transmission gears, which seemed to be meshing properly. It appears to me the problem must be the centrifugal clutch, or rotor, as it is identified in the operator's manual.
1.) How do I determine if the rotor is the problem?
2.) How do remove the rotor? I didn't see any set screws or anything similar that holds it onto the shaft. Also, since the engine shaft is not exposed, am I correct that a gear puller won't help me? I think the rotor might be screwed on, so I would have to stop the engine from turning when I screw the rotor off.
Even though the tiller is a few years old, it's been very dependeable and if I can get a few more years out of it for the cost of a $25 rotor, it should be a good deal.
Thank you very much in advance for your assistance.
Ernie
ANSWER: Hello Ernie:
The Clutch on this Tiller is Just Like a Chainsaw Clutch. As the Rpms Increase the Springs Stretch and Allow the Clutch Pawls to Engage the Drum and Turn Shaft to the the Tines. From your Description it Sounds like the Drum or the Rotor/Clutch. If the Springs and Pawls on the Rotor/Clutch are Good, then the Drum is Actually the Cause of the Problem. I Usually Suggest Replacing Both the Drum and Rotor/Clutch.Are there Any Signs that the Pawls have Been Slipping Inside the Drum? Is the Inside of the Drum Smooth or is it Rough from the Rotor/Clutch Pawls Slipping. The Rotor is Screwed Onto the Crankshaft, Much like Chainsaw Clutch. Purchase a Bolt that is the Same Diameter and Threads as the Spark Plug. Usually a 4" Long and Threaded 3" will Work. Thread the Bolt Into the Spark Plug Hole until the Bolts Contacts the Piston. Now Using the Bolt to Lock the Piston, Remove the Rotor/Clutch from the Crankshaft by Hitting the Rotor/Clutch with a Flat Punch and Hammer. The Rotation is Reverse of the Operational Rotation of the Engine. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Thanks for the info - I'll remember that for future reference. In the meantime, I did some additional investigation into the transmission gears and determined that they were the problem. Most of the gear teeth were good enough to mesh, but there were a couple teeth that were worn down a little more than the rest. When those teeth lined up with a bit of a flat spot on the worm gear, and the tiller tines were restrained, the combination was enough to make it slip intermittantly. So now the answer is 2 new gear shafts, which I assume will probably make the repair cost more than what is reasonable for a tiller of this age.
Answer Hello Again Ernie:
Great!!! I'm Glad you Located the Cause of the Problem. As for the Repair or Replacement; My Tiller is Approx 35 Years Old and Was My Grandfathers. The Engine has Never Been Rebuilt and is Still Running Good. Other Than the Clutch Replacement, Tines Replaced 3 Times and the Worm Gear Replaced Once. I Like the Tiller. I Could Purchase a New One; But I know what I Have and I May Blow the Engine Tomorrow. Then I can Decide if a New Engine or a Whole Tiller. LOL. As you can See, the Decision to Purchase or Repair is Completely Yours. I'm a Fan Of: If it I can Repair it and it will Give me Good Service, then I Fix it. Hope this Helps. I am here if you Require more Assistance. Let me know what you Decide, Please. Thanks.
Good Luck
Respectfully
John
