The Mall 4MG was a large American one-man chainsaw produced from 1955 to 1957. Its 105cc reed-valve engine developed 5.5 horsepower, driving an unusually large 9/16-inch chain through a direct-drive system and centrifugal clutch.
The example pictured here, which we saw in a chainsaw display, was made in the United States by the Mall Tool Company of Chicago. Its ID plate shows assembly number 43660A and serial number J-41546. A 1955 Eaton’s advertisement (further below) described the 4MG as a new, streamlined model and listed it at approximately 32 pounds with a 24-inch bar. That was considered relatively light and manageable by the standards of the period.
Specifications
| Specification | Details |
|---|---|
| Manufacturer | Mall Tool Company |
| Model | 4MG Direct Drive |
| Assembly number | 43660A |
| Production years | 1955–1957 |
| Country of manufacture | United States |
| Manufacturer location | Chicago, Illinois |
| Operator configuration | One-man chainsaw |
| Engine type | Air-cooled, single-cylinder two-stroke |
| Displacement | 6.45 cu. in. / 105cc |
| Bore | 2.25 in. / 57mm |
| Stroke | 1.625 in. / 41mm |
| Cylinder | Chrome-plated aluminum |
| Intake system | Reed valve |
| Advertised output | 5.5 brake horsepower / approximately 4.1kW |
| Maximum engine speed | 5,000 rpm |
| Carburetor | Tillotson HP diaphragm carburetor |
| Air filter | Skinner ribbon-type element |
| Ignition | Bendix Scintilla magneto |
| Ignition timing | 30 degrees before top dead center |
| Breaker-point gap | 0.018–0.020 in. / 0.45–0.51mm |
| Flywheel-to-coil gap | Fixed |
| Spark plug | Champion J6J |
| Spark-plug gap | 0.025 in. / 0.63mm |
| Crankshaft bearings | Ball and roller bearings |
| Starter | Mall automatic rewind starter |
| Clutch | Two-shoe Fairbanks Morse centrifugal clutch |
| Drive system | Direct drive |
| Construction | Die-cast light-alloy housings |
| Handle system | Rigid full-wrap front handle |
| Anti-vibration system | None |
| Chain brake | None |
| Chain oiler | Manual pump built into the clutch cover |
| Fuel capacity | 1 US quart / approximately 0.95 litres |
| Factory fuel mixture | ½ pint of oil per US gallon of gasoline, equivalent to 16:1 |
| Period fuel recommendation | 72–84 octane regular-grade gasoline |
| Period oil recommendation | SAE 30 non-detergent oil or Mall oil No. 48411 |
| Chain pitch | 9/16 in. / approximately 14mm |
| Original chain type | Mall chrome-plated side-planer chain |
| Listed guide-bar range | 15–24 in. / 38–61cm |
| Period advertised weight | Approximately 32 lb / 14.5kg with a 24-inch bar |
| Original color | Mall red |
| Period Canadian price | $327 with a 24-inch bar in a November 1955 Eaton’s advertisement |
| Photograph serial number | J-41546 |
| Photograph bar | Mall bar apparently stencilled for a “26 inch chain” |
The housing material is one specification on which period and collector sources differ. The modern model profile describes die-cast magnesium construction, while the 1955 Eaton’s advertisement (below) says die-cast aluminum.
NEW MALL CHAIN SAWS
Model 4 M.G.
A new model gasoline-powered model in streamlined styling. Easy to handle. Automatic one-hand rewind starter. Automatic centrifugal clutch requires no controls. Housings are die-cast aluminum. Manual type oiler for chain, sprocket and bar. Light weight about 32 lb., with 24-inch guide bar.
EATON Price, each …………… $327.00
Model O.M.G.
A good quality gasoline-powered chain saw. Many new improved features. Weight about 27 lb. New crank-pin bearing to help reduce friction. Self-energizing automatic clutch. Starter on the sprocket shaft. Automatic chain oiler. Float type carburettor, 1 cylinder engine at 3.6 h.p. 18″ cutting bar.
EATON Price, each …………… $279.00
Interesting Mall 4MG facts
The 9/16-inch chain is considerably larger than the .325-inch and 3/8-inch chain commonly found on modern saws. Its large side-planer cutters are a particularly striking feature.
The fuel cap on this example still carries Mall’s original mixing instruction of half a pint of oil per gallon of gasoline, which works out to 16:1. This is the historical specification, not necessarily a recommendation for operating a restored saw with modern fuel and oil.
Remington Arms purchased Mall Tool Company in June 1956, partway through the 4MG’s production life. The Mall name was dropped soon afterward, placing the 4MG among the last chainsaws produced under the independent Mall identity.
