1950s Locke 70 Triplex Reel Mower (Field Guide)

The Locke Model 70 is a three-reel mower, but its name alone does not identify the engine, fuel, reel settings, or service limits. Before operating or ordering parts, read the machine and engine identification plates, then match each detail to suitable service information. Inspect the guards, controls, and all three cutting units before a cautious test run.

A vintage mower can look complete and still hide a safety or setup problem. I treat the identification plate as the starting point, not the model name: parts and controls may differ, and a wrong assumption about engine fuel or reel adjustment can cause damage.

This field guide covers safe identification, inspection, setup, mowing, service, and storage. It does not assign specifications that must come from the particular mower’s tags or applicable documentation.

Identify the mower and engine before service

The Locke Model 70 is a triplex reel mower, meaning it has three reel cutting units. That identifies the general cutting layout, not every detail of an individual machine. Record the mower’s serial or data plate and the engine’s full identification before researching settings or buying parts.

Look for the mower’s make, model, and serial information, then locate the engine tag. Record the engine make, model, type, and code exactly as shown. A partial number can lead to the wrong manual or replacement component, so take a clear photo as well as writing it down.

The engine identification is essential for fuel and operating settings. Do not assume this mower uses straight gasoline or a gasoline-and-oil mix. Use the fuel grade, oil type and capacity, and any fuel-to-oil ratio specified for the identified engine. Likewise, get idle and governed-speed settings from that engine’s applicable manual. Do not guess a maximum speed or adjust the governor by ear.

The Model 70 designation does not establish reel diameter, blade count, bedknife profile, cutting height, belt or chain arrangement, fastener torque, or drive adjustment. Check the mower’s parts or service information before changing these. If the tag is missing or unreadable, identify the actual components and seek competent service information rather than treating a similar-looking mower as an exact match.

Next step: Gather these details before ordering parts or adjusting the engine or cutting units.

Inspect and prepare the mower safely

A pre-use inspection is a deliberate check of the machine before starting, not a quick look at the engine. Confirm the mower is stable on level ground and that all three reels, guards, belt or chain covers, controls, and any operator-presence or shutdown devices fitted to that mower are present and work as intended.

Wear eye protection, hearing protection, sturdy footwear, and close-fitting clothing. Keep bystanders clear, especially near the reel discharge. Before touching a reel or drive, stop the engine, remove the key if fitted, and prevent unintended starting. Wait for all motion to stop. Never put a hand into a reel to clear a jam; even a reel that is not powered can move and cause severe injury.

Check tires or wheels, steering, brakes, and controls. Inspect fuel lines, wiring, and visible fluid lines for leaks, damage, or improvised repairs. Look for loose fasteners, cracked or bent cutting parts, missing guards, and debris around the reels and discharge path. Do not operate with a damaged guard or a control whose function is unclear.

Clear stones, wire, and other projectiles from the mowing area. Check that each cutting unit is secure and that no foreign material is caught in its drive. If the mower must be raised for inspection, support it securely with suitable mechanical support; do not rely on a jack alone.

The manufacturer’s instructions and applicable workplace rules govern safe work. OSHA 1910.266 is a logging standard, and ANSI Z133 covers arboricultural operations; neither provides Locke Model 70 adjustment specifications.

Next step: If a safety device is missing, a leak is present, or you cannot verify how a control works, pause and get the issue assessed before mowing.

Set up the reels and cutting height

The bedknife is the fixed cutting edge that works against the rotating reel blades. Reel-to-bedknife adjustment is specific to the cutting unit and its condition; there is no safe universal setting to apply just because the mower is a Model 70.

First, identify the reel and bedknife parts and find the matching service procedure. Record the reel diameter, blade count, bedknife profile, and specified adjustment if the correct documentation provides them. Check all three units. Do not tighten an adjustment until the blades bind: excessive contact increases friction, heat, and wear, and may damage the cutting parts.

Measure cutting height on a flat reference surface with a suitable height-of-cut gauge. Measure each unit and compare the readings. Set all three to the intended height for the turf and the documented setup, then verify the readings again. A single height cannot be prescribed for every site or reel configuration.

Use only the fastener torque and belt or chain adjustment limits stated in applicable documentation. If those values are unavailable, do not invent them. Identify the hardware and seek competent service guidance before loosening, tightening, or changing the drive.

Sharpening and backlapping require the correct procedure, tools, and guarding for the machine. Isolate the engine and drive before service. After adjustment or sharpening, check that the reels turn freely and that the cutting action is even across the width. If you cannot confirm safe isolation or correct setup, use a qualified reel-mower service shop.

Next step: Keep a written record of each unit’s measured height and any service performed. That makes it easier to find uneven setup later.

Start, test, and mow in a controlled sequence

A controlled first run helps reveal faults before the mower is working across a lawn. Start and warm the engine only as its manual directs, with the mower stable and cutting controls disengaged where fitted. Keep hands, feet, and clothing away from reels and drive parts at all times.

Test steering, stopping, and reel engagement at low speed in a clear area. Engage the reels only at the operating condition and engine speed specified for the machine. Do not compensate for a poor cut by raising engine speed beyond the documented setting.

Mow at a controlled pace. Avoid abrupt turns that can scuff turf, and do not mow on slopes or wet, unstable ground beyond the mower’s documented limits. Stop immediately if you notice unusual vibration, contact noise, loss of control, or a jam. Shut down and isolate the machine before investigating.

At the end of a pass, disengage the cutting units and stop on level ground. Set the parking brake if fitted, stop the engine, and prevent restart before inspection. Let hot parts cool before cleaning or refueling. Use a brush or suitable tool to remove clippings, keeping hands away from the reels.

Next step: Make the first test cut in a clear area and check for even cutting and normal operation before continuing.

Maintain and store the Model 70

Regular care focuses on the cutting units, drive, engine, and age-related parts. Follow the mower’s service schedule where available and the identified engine’s manual for oil changes, air filtration, and ignition and fuel-system service. A machine’s age makes careful inspection important, but it does not justify substituting parts without checking compatibility.

Clean and inspect reels, bedknives, bearings, drives, and guards. Look for cracks, bends, looseness, corrosion, or excessive wear. Check fuel hoses, seals, wiring, and covers for deterioration. Replace defective parts with compatible components, not improvised substitutes. If fuel or oil has been left in the machine, follow the engine maker’s guidance for inspection and service before starting.

For extended storage, follow the identified engine maker’s fuel-system instructions. Do not leave unidentified or degraded fuel in the system. Store the mower dry, stable, and protected from accidental starting. Clean and dry the cutting units, and protect bare metal from corrosion without contaminating the turf-facing cutting edges. Do not loosen or relieve components unless the machine documentation directs it.

Before returning the mower to service, inspect the fuel lines, tires or wheels, controls, guards, reels, and fasteners. Verify the stopping function and test cutting performance in a clear area.

Next step: Keep the engine and mower identification, service notes, and measured settings together so the next seasonal check starts with facts rather than guesses.

Field setup scenarios

These examples are practical decision paths, not claims about a documented owner or a particular surviving mower. They show how to respond when a Model 70 arrives with missing information or an unclear symptom. In each case, identification and safe isolation come before adjustment.

Engine tag is unclear

If the engine tag is damaged, do not choose fuel or speed settings based on the mower’s decade or appearance. Photograph the tag, note any readable marks, and have the engine identified before fueling or adjusting it. If identification remains uncertain, do not start it until the correct requirements are established.

One reel cuts differently

If one strip looks different from the others, first stop and isolate the mower. Compare the measured height on all three units, then inspect the affected reel and bedknife for damage, debris, or uneven wear. Use the correct service procedure to adjust or sharpen; do not simply tighten the reel until it contacts hard.

A reel is jammed

Stop the engine, prevent restart, and wait for all motion to cease. Keep hands out of the reel and drive. Use a suitable tool to clear debris only when the machine is securely isolated. If the reel still will not turn freely, or parts appear bent or damaged, seek qualified service before running it.

Next step: Treat unusual behavior as a reason to inspect, not a reason to bypass a guard or force a setting.

Frequently asked questions

Is the Locke Model 70 a triplex reel mower?

Yes. It is a triplex mower with three reel cutting units. Confirm the condition and equipment fitted to the individual machine before operating it.

Does “Model 70” identify the engine?

No. Read the engine’s make, model, type, and code from its tag. Use those details to find the correct engine service information.

Does this mower use premixed fuel?

The model name alone does not establish the fuel type. Follow the requirements for the identified engine; do not assume straight gasoline or premix.

What engine speed should I use?

Use the idle and governed-speed settings in the applicable manual for the identified engine. Do not guess a speed or adjust the governor by ear.

What reel-to-bedknife setting should I use?

Use the procedure and setting for the identified reel and bedknife. The Model 70 designation alone does not provide a universal adjustment value.

How do I set cutting height?

Measure each cutting unit on a flat reference surface with a suitable gauge. Set all three to the intended height, then measure again to confirm they match.

Can I clear a jam by hand when the engine is off?

No. Isolate the ignition and drive, wait for all motion to stop, and use a suitable tool. Never reach into a reel to pull out debris.

What should I do if the correct service information is missing?

Record the mower and engine identification, identify the installed components, and seek competent service help. Do not invent torque, drive-tension, or reel-adjustment values.

What should I check before mowing after storage?

Inspect fuel lines, wheels, controls, guards, fasteners, and all three reels. Confirm the stopping function, then test the mower in a clear area before cutting turf.

(This article was written by one of our staff writers, Harrison Croft. Visit our Meet the Team page.)