Small Engines (Lawn Mowers, etc.): pull rope and spring messed up on craftsman, craftsman 917, briggs stratton

Question
My pull rope broke on my craftsman 917.377190, so I took the top off and routed the string through and knotted it on one side...I got it to wind up but couldn't get any tension or retraction.  I then popped the spring out and it unwound so I'm thinking that top part is going to have to be replaced...any ideas???thanks

Answer
RIC
Broken starter ropes or failure to retract are both repairs that are fairly easy. However, the spring can be nasty as it is under tension (or should be when reassembled). This can be risky if you are not familiar with the internal construction as you disassemble the unit.
The cause of a broken cord is obvious. The cause for a failure to retract could be a broken spring, tangled or frayed rope, or some other mechanical failure. A broken spring will require total disassembly of the starter mechanism - fortunately there really isn't that much involved.

With some designs, it is possible to replace the cord without fully disassembling the starter mechanism - by threading the cord in and tying a not in the end - but after rotating it several turns to put the proper tension on the spring. This is relatively safe but may be frustrating as 3 hands are sometimes needed.

Where safe disassembly is not obvious, I would recommend that you refer to a book on lawn mower or small engine repair from the library or the service manual for the mower, if possible. You may be able to find specific step-by-step instructions which will minimize your risk of injury from an encounter with an uncontrolled spring.


When the rope pulls out and retracts normally - but doesn't do anything else - the most likely cause is a problem with the one-way clutch. This may be part of the spring-rope assembly - usually removable as a unit - or attached to the flywheel. The most common problems are gummed up lubrication or a broken spring or other damaged or worn parts. For common engines:

On Briggs & Stratton starters, the clutch is often part of the flywheel nut assembly. The entire unit can be easily removed and replaced if it fails to engage reliably.