Wind To Start Lawn Mowers

Article by Mark Trotta

Recently while searching for small engine parts online, I spotted an ad for a Briggs & Stratton wind-to-start handle. I haven't seen or even thought about wind-to-start mowers for years, and it brought back a lot of memories.

wind-up start lawn mowers

Once Upon A Time...

Like many young boys, one of my chores back in the day was cutting the lawn. It was my first encounter with a gas engine, and started my lifelong affliction with internal combustion engines.

In the early seventies, our family lawn mower was a Sears Craftsman with a crank-to-start Briggs engine, similar to the one in the picture below. These were also referred to as "inertia start" motors.

inertia start lawn mowers

I always thought the wind-up crank was fun, and it was probably the only way a twelve-year-old boy could have started a lawn mower. To be honest, I was more interested in running the engine than making the lawn look good.

Wind-Up Spring Starter

On vertical-shaft lawn mower engines, the wind-up handle would be on the top of the motor. Less commonly, they were fitted to horizontal-shaft engines, which had the wind-up handles on the side.

Starting Procedure:

Providing the engine was in good shape, the wind-to-start system worked well, and the motor started. But if the motor was tired or out of tune, it would take several tries to start. The starting process would then have to be repeated.

The folding wind-up crank had it's popularity in the sixties and early seventies. They were most common on Briggs & Stratton and Tecumseh powered lawn mowers, and a few other brands had them too, such as Lauson. The Toro brand primarily used Tecumseh engines. Their wind-up starter was called "Impulse Start".

Lauson wind-up starter

Wind To Start - Good Points

For some, a wind-up starter was easier than a pulling a rope to start their lawn mower. As a kid, it was probably the only mower I was able to start - I wasn't yet big enough to pull a recoil starter. Another plus was, if a person had back problems, it would take less effort than yanking and pulling on a rope.

Wind To Start - Bad Points

Looking at a wind-start assembly, you can see that it was more costly to manufacture than a rope-pull starter. That's one reason why they stop producing them. But the main reason is the potential harm they could cause.

inertia start lawn mower

Although the wind-up spring mechanism was heavy and would rarely break, they did break. The spring was about an 1/8" in thickness and about two feet long. Due to the nature of a heavy coiled spring, if it was suddenly released, it could certainly cause bodily injury, which was known to happen.

wind to start lawn mowers

Another safety issue with the wind-up starter was, if the mower was cranked but not started, it was possible for the mower to accidentally start if bumped or jarred. To remedy this, at least one company offered a wind-to-start lawnmower that required a key to lock/unlock the crank handle.

Since the wind-up springs were dangerous to replace, many mechanics refused to repair them. More often than not, when a wind-to-start mower gave trouble, it was replaced with a pull-rope style. The conversion was simple; remove the wind-to-start housing, throw it away, and replace it with a pull-start housing.

Early vs Late Design

My vintage Briggs & Stratton repair manual shows two types of wind-to-start assemblies. The original design (early 1960s) seemed to have a minor design flaw. If the start knob was engaged while the engine was running, the control knob on the housing could shear off flywheel fins.

wind to start lawn mowers

A later design removed the starter switch off the blower housing, and up onto the mower handle. The other end was a bracket controlled by a cable. This removed potential danger away from the operators hands.


Modern Wind-Up Technology

Several years ago, Stihl Power Tools began producing a start system that utilizes both pull-rope and wind-up spring technology. Their "ErgoStart" system features an additional spring between the crankshaft and the starter rope rotor.

This system was designed to have less effort and slower pulls than a conventional recoil-starter. Stihl products that feature the ErgoStart system will have the letter "E" in the model name.


Related Articles:

How To Restore Engine Tin
Vintage Briggs & Stratton Engine Identification
Vintage Tecumseh Engine Identification
Lauson Small Engines