Here is another underrated member of the Big Red family – the Honda QA50. Although not as short-lived as the ST90, this minibike was shunned for its second-rate speed and crude handling. However, the riding community has begun to gravitate toward this bike due to nostalgia and its rarity. And you are about to discover what makes the Honda QA50 endearing in this guide.
The Honda QA50 is a 49-cc pocket bike produced from 1970 to 1974 and released in the market until 1975. An off-road version of the famed Monkey Bike, the QA50 sported candy-colored panels, a fully-enclosed exhaust with a Krizman spark arrestor, a 2-speed gearbox, and foldable Swivel-Lok™ handlebars.
Despite its sheer simplicity, the Honda QA50 is as fun and funky to ride as it looks. And these traits are, by no means, detrimental to the minibike’s reputation. It may not have the Honda Z50’s sport-tourer mannerisms, but it overcompensates for this flaw by being part of every child and adult rider’s off-roading journey.
About the Honda QA50 Minibike
Big Red’s revolutionary advertising slogan, “You meet the nicest people on a Honda,” shattered the stereotype that motorcycles were only for tough and rebellious. The Japanese firm almost single-handedly triggered a paradigm shift in how consumers viewed fun and riding.
But the ad alone did not do the trick. The reason behind the effectiveness of the slogan was Honda’s follow-through – a slew of breakthrough, approachable motorcycles, including the Honda QA50.
The Honda QA 50 is the off-road incarnation of the Honda Z50, a detuned version of the latter introduced by Honda in the U.S. market in 1970. It had an OHV power mill with a pushrod design, an 80°-inclined, single-cylinder arrangement, and a 2-speed automatic transmission. The bike was clad in mesmerizing colors like Gypsy Yellow and Scarlet Red and was safe enough to be ridden by a five-year-old.
Throughout its production, the Honda QA50 released four generations of trims in six years. Earlier models offered more body paint options and the bike’s trademark Swivel-Lok™ handlebars. However, these changed in 1973, with post-1970 models having stationary bars and a single color scheme.
The next section details the most significant upgrades applied to the QA50.
- Molding around the seam of the fuel tank changed from black rubber molding to chrome.
- Honda QA50 fenders were finished in white with a blue or red stripe that conformed with the bike’s main body color (instead of matching the fuel tank).
- The front forks were painted silver and the frame black instead of a single color for both.
- Handlebars changed from its patented Swivel-Lok™ to stationary bars.
Honda QA50 Specs & Features (K0 – K3 Models)
The Honda QA50 is brought to life by an air-cooled OHV (pushrod) engine. Its single-cylinder arrangement consists of cast iron, angled at 80° from vertical, with a piston displacement of 49 cm³ (3.0 in³).
The bore-stroke ratio is 42 x 35.6 mm (1.654 x 1.405 inches), while the compression ratio is 8.5:1. Its stock carburetor (although unspecified in the manual) can be upgraded to an aftermarket PZ20 for better top-end performance.
Overall, this engine configuration makes for a bone-stock top speed rating of 30 mph (48.3 km/h) and a horsepower of 1.8 hp (1.3 kW) @ 5,000 RPM. But according to minibike-dedicated forums, adult riders can hit “25-40 mph in full tuck” on the QA50 Honda. However, no specific rider weight is mentioned for this reported speed rating. Some even claim that they can outrun a QA50 during their adolescence.
Engine mods and tweaking main jetting to #114 or #130 (among other changes) can give you a slight lift in performance. However, remember that jetting settings for the K0 models (1970–1972) are different from the rest of the bike’s incarnations when doing a top-end rebuild.
Additionally, 1970–1973 QA50s had a screw-in float needle valve seat, while the latter models did not. Knowing these details should guide you in choosing the appropriate rebuild kit for your wheeler.
Fuel & Lubrication
Fuel tank capacity is 4.5 L/1.2 US gallons of low-lead or unleaded gasoline. This capacity is better than the Honda ST90’s. Moreover, you can switch the fuel variant to regular-grade gasoline if unleaded is unavailable.
Lube-wise, Honda recommends high-detergent, premium-quality 4-stroke oil or its equivalent for the QA50’s wet sump system. For best results, engine oil should be SAE 10W-40 or 20W-50 with a minimum API API grade of SJ meeting JASO T903 MA standards.
The following viscosity grades (seen below) are permitted following ambient temperature or changes in altitude and riding conditions:
|Above 59° F
|32° to 59° F
|SAE 20 or 20W
|Below 32° F
A 2-speed (wide-ratio) transmission and a semi-automatic multi-plate clutch assembly deliver power to the ground and make handling predictable and stable – perfect for young riders.
A 420 O-ring chain (view on Amazon) with 78 links plus joint handles wheelspin and can be replaced with same-spec chains with 120 links in case of wear or damage. As for gear ratios, stock values are in the table below:
|Primary Reduction Ratio
|Transmission Gear Ratio – I
|Transmission Gear Ratio – II
|Final Reduction Ratio
Like the ST90, it has a Contact Breaker Point ignition system with a kick-starter, is wired for 6 volts, and comes with a Flywheel A.C. generator serving as its charging system. An NGK C7HSA or Nippon Denso U22 FS spark plug is responsible for spark ignition. In case of unavailability, the C7HSA has several other replacements, which you can find via this spark plug finder.
As with most dated minibikes, it is best to convert its wiring harness to support a 12-volt electrical system – in addition to performing a regulator/rectifier and stator upgrade. Doing this step will enable you to swap out the stock battery for a 12V (6 Ah)/10 HR YTZ7S battery (view on Amazon) format with assembled dimensions of 113 x 70 x 105 mm (4.44 x 2.74 x 4.12 inches – L x W x H) and add a lighting system to your QA50.
Tires & Brakes
Stock tires consist of 12-inch 4.00-5 (2PR) front and rear Nitto tires mounted on cast aluminum rims. Recommended cold-tire pressure is unspecified in the owner’s manual, but we can assume it is at 98 kPa (1.0 kgf/cm2, 14.2 psi) – the same as the Z50. Depending on ambient temperatures or riding conditions, this can be adjusted accordingly.
The manual made no mention of brake type and specs too. But according to Web Bike World, cable-operated front and rear drum brakes complete the QA50’s tire-and-wheel assembly.
Enclosed in the Honda QA50’s tubular steel frame (66° caster angle; 1.7 inches/43 mm trail) are front telescopic forks with no corresponding rear suspension unit but pair with a rigid rear end. Again, there are no details for the wheelbase, minimum ground clearance, or turning radius specified in the service manual.
But given that the Z50 and QA50 are of the same class, it would be safe to say ground clearance is 170 mm (6.7 inches), the wheelbase is 880 mm (34.7 inches), and the turning radius is 2.6 meters (8.6 feet) at least.
Overall dimensions are 1,200 x 610 x 835 mm (47.2 x 24 x 32.9 inches – L x W x H) with the handlebars in the locked position, making the pocket bike longer but wider and taller than the Honda Z50 Monkey Mini Bike.
The saddle is somewhat slanted and sits slightly taller than the fuel tank. The dry weight is 38 Kg (84 lbs.). However, load limit capacity and GVWR are unspecified in the owner’s manual.
Honda QA50 parts were made available in different color schemes throughout its 6-year run. K0 models had Honda QA50 plastics in Gypsy Yellow, Sprout Green, and Scarlet Red, with tank-matching fenders and no stripes.
K1 versions had Hawaiian Blue Metallic and Candy Ruby Red plastics. K2 iterations were similar to K1 models but available in Candy Orange. And finally, K3s had a fuel tank with chrome molding and only one color option – Mars Orange.
Front forks and other components received minor cosmetic touches, but the most apparent was the handlebars. The bars were changed from a Swivel-Lok™ to a stationary type in 1973, adversely affecting the bike’s portability.
How Much Is a Honda QA50 Worth?
|Year – Trim – Model Number
|1970 Honda QAK0
|$580 – $2,530
|1970 Honda QA50
|$740 – $4,085
|1971 Honda QA50K0 50
|$740 – $4,085
|1972 Honda QA50K0 50
|$575 – $3,040
|1973 Honda QA50K1 50
|$490 – $2,440
|1974 Honda QA50K2 50
|$490 – $2,440
|1975 Honda QA50K3 50
|$485 – $1,920
Pre-owned QA50s keep their value quite well, with retail pricing ranging from $575 to $8,000. Many units are available on Craigslist, Smart Cycle Guide, and other well-known trader sites, and most resale bikes are K0 models.
A big chunk of these are near-stock units with peeling fender paint and visible erosion in some parts. Some are restomod bikes, while others (usually above $6,000) are rare single-owner units with retouched body paint, rebuilt power mill, powder-coated frame, and NOS tubes and braking installed.
Honda QA50 vs. Honda PC50
One interesting thing about the QA50 is that it is often confused with Big Red’s very own moped, the PC50. While it is easy to assume that these bikes are gravely similar, they actually are not.
The Honda QA50 was created as an off-road version of the famed Honda Z50. The QA50 was more rugged but was actually a detuned version of the Monkey Bike. On the other hand, the PC50 was made for the European market. It may have had the same jug and head as a QA50, but it looks much sleeker than the former due to longer legs and thinner tires.
Not only that, but the PC50 has its fuel tank tucked under the seat, whereas the QA50 has its tank atop the frame, like a traditional motorcycle setup. If anything, the features of the PC50 resemble that of the Super Cub series than the QA50.
The Infamous 2nd Gear Problem
Because of how the gearbox was configured in the factory, the movement of the shifter’s pull shaft in its slot ends up being restricted. To remedy this, you will need to take the shifter out, work on the grinding wheel, and round off its corners so that it pushes into the hilt and can engage the 2nd gear.
You may also want to check other relevant components like the flange, gear selector, and grinding wheel if they need to be cleaned or machined.
A force to be reckoned with in the motorcycling arena, the Honda Motor Company Ltd. is one of today’s most successful global automotive manufacturers – and for good reason. Founded by Soichiro Honda in 1946, the Japanese firm evolved from the ideation of automotive parts and motorized bicycles with surplus engines to the mass-production of automated military aircraft propellers, race cars, and class-leading motorcycles like the Honda QA50.
Honda continues to be recognized for its monumental contributions to electric automobiles, motorsport vehicles, energy solutions, and other industries.
Conclusion – Honda QA50 Minibike Review
The Honda QA50 may not be a sport-tourer like the Z50 or other bikes of the same category. But it is becoming a collector’s favorite due to its rarity. However, this does not necessarily mean you can no longer have a blast on the bike.
Whether purchasing one for the youngster at home following in your footsteps or keeping the two-wheeler all to yourself, you are guaranteed fun times and a flood of fond memories on this iconic and good-natured pocket bike.
Kris is an avid off-roader and outdoor enthusiast who loves to brave the elements and take on challenging terrain. He also enjoys sharing his passion and knowledge with others so that they, too, can appreciate the ride.