Suzuki Mt50 Mini-Bike
SUZUKI MT50 MINI-BIKE
Automatic Lubrication, Reed Valve Aspiration Are Features Of This Diminutive Fun Machine
SUZUKI'S ENTRY into the mini-bike field is somewhat overdue, but the finished product was well worth the wait. Lavish use of high impact plastics, sound engineering practice and innovative styling set the Suzuki toward the front in mini-bike circles.
Riding the Trail Hopper proved to be quite a surprise for most of us on the staff. It's quite a bit more powerful than its rated 3 bhp would lead you to believe, and the controls are nicely laid out and easy to operate. The left handlebar lever operates the rear brake, and the shift lever is operated by the left foot. A conventional twistgrip and front brake lever complete the controls arrangement.
The engine, which is taken from Suzuki's successful F50 step-through is mechanically quiet, powerful, smooth and quite simple in design, which contributes to its reliability. A rather unique feature is the use of a reed valve which opens and closes automatically as dictated by pressures in the crankcase. After the inlet charge has been sucked into the crankcase, pressures neutralize and allow the reed valve to spring closed, preventing any blow-back into the carburetor. Low speed running and fuel economy are greatly improved.
Fresh oil for lubrication is fed into the engine by an oil pump through check valves. The left-hand channel supplies oil directly to the drive side main bearing and the connecting rod big end bearing, while the right side orifice opens directly into the inlet tract and supplies lubrication for the piston and connecting rod small end bearings. The right hand main bearing is lubricated by transmission oil. Throttle opening and engine rpm determine the rate of delivery and ensure proper lubrication at all times.
The centrifugal cum multi-disc wet clutch begins taking up the drive when engine speed reaches approximately 2 000 rpm. Shifting the three-speed transmission is accomplished by pressing the gear shift lever which releases the clutch and simultaneously selects the next gear. Our test bike was rather harsh during shifts, but we understand that some of the jerking from the initial movement of the shift lever can be reduced by substituting SAF. 10 oil in the transmission for the recommended SAE 30.
The brakes rate excellent in effectiveness, but the front brake is just a trifle severe for dirt riding. Suspension is adequate for all but the roughest cross country riding and compares favorably with any other mini-bike on the market. Wide, 3.50-8, 4-ply tires on disc wheels complete the drive train, and are a requirement for a dirt machine of this type.
CYCLE WORLD IMPRESSION
Although the Trail Hopper is equipped with lighting equipment and a horn, a sticker on the top fork crown warns against riding the machine on public roads. It is intended to be a trail machine, and it fulfills this purpose very well.
Muffling is accomplished by an efficient one-piece unit which incorporates a USDA-approved spark arrestor. The rider is protected from the hot exhaust pipe by an attractive piece of highimpact plastic, and a companion piece on the other side covers the oil tank. The fuel tank is covered by a large piece of the same plastic material which also effectively hides the ignition coil and the wiring. Seat height and handlebar positions are adjustable to suit riders over 5 ft. tall and are easily altered. Construction details and finish are up to Suzuki's traditionally high standards, but we see the need for an engine shield or skid plate to protect the exhaust pipe and cylinder from rocks.
Generally speaking, Suzuki has scored very highly on our list of minibikes with a well conceived and finely executed machine. It is a most worthy addition to their line. [O]
