Rewind starters, also known as recoil or retractable starters on small engines can be a source of problems when the main rewind spring becomes loose or stiffens up. The Troubleshooting section gives you an idea of things that usually go wrong.
There are two types of starters, depending upon the engagement mechanism. Clutched starters are the most complicated. Ratchet starters which literally work like ratchet wrenches are the second basic category.
Troubleshooting Starter Motors
A sluggish action If the starter rope becomes stiff and retracts slowly, assume dirt is the problem. Cold weather that coagulates the grease on the mainspring has a similar effect, as does misalignment of the starter with the flywheel cup.
Broken cord The cord or rope is usually the first part to fail, especially on hard-starting engines that aggravate their operators. Worn rope ferrules contribute to the problem.
• Failure of the cord to retract If the whole length of the cord extends out of the housing, the mainspring has either broken or lost its anchor. Partial retraction usually comes about because of a weak spring. Increasing the pretension on the spring sometimes helps, although the surest cure is to replace the spring. Severe starter/flywheel misalignment will also leave the rope dangling.
• Failure to engage the flywheel On clutch-type starters, expect to find a loose clutch retainer screw, a worn or distorted brake spring, or oil on the friction surfaces. Ratchet starters fail to engage because of broken or twisted ratchet springs or rounded-off ratchet tips. These matters are discussed in more detail later.
• Noise from the starter as the engine runs Check starter/flywheel alignment.
Before dismantling a starter, the mainspring must be allowed to uncoil as much as the housing permits. It will still contain energy. Disarming is
accomplished either by detaching the cord handle or by partially disengaging the rope from the sheave. The handle can be removed by untying the knot or by cutting the cord. Then, using your thumbs as a brake, allow the sheave to unwind. Count the number of turns it takes to be able to apply the same preload upon assembly.
Replace the spring if broken, distorted, or too weak to retract the cord. Otherwise, leave it undisturbed. Replacement springs usually are prewound. Some come housed in a retainer and install as an assembly. Others are secured by a wire clip. Align the outboard spring end with the housing anchor and press the spring out of the clip, which is then discarded. Whether you use a winding tool or install the spring by hand, it is critically important to orient the spring relative to the direction of engine rotation.
The replacement starter cord, or rope, should have the same diameter, length, and weave as the original and it should be made of unalloyed nylon. If the length is unknown, secure the cord to the sheave and wind until the spring coil binds. Allow the sheave to unwind for one or two turns and cut the rope, leaving enough for handle attachment.
Purchasing cord by the engine maker’s part number should obviate problems with material differences.
Important points are:
• The mainspring winds tighter as the flywheel is turned in the normal direction of engine rotation. If you trace the curvature of the spring from the fixed outer end to inner end where the sheave anchors, your finger would move in a counterclockwise spiral.
• Eaton-style friction clutches assemble without lubrication. Should the clutch slip, verify those friction elements are dry, the center screw is tight, and the drag spring undamaged.
• Failure of the cord to retract can be caused by loss of pretension, a
weak main spring or by a misalignment between the starter and flywheel hub.
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