info on 1980 suzuki jr50

[ellandoh]

just had a 1980 suzuki jr 50 given to me for the nephews to play on.

i need some info for this vintage machine. first is what plug goes in it. there is a br9es which i can tell is just screwed in to keep bees from building a nest . also it appears as though it is an oil injected 2 stroke but the header pipe appears to be a 4 stroke style pipe , can anyone tell me if this is 2t or 4t , my guess is 4t because i see no reed cage assembly , if so what oil goes in the injector reservoir?. last question is where can i get parts and info on this machine, is there a website

 

[MCMAN56]

It is an oil injected two stroke but does not have a tuned pipe. The oil tank is sort of under the seat. I do not remember the plug but a #9 sounds cold. It is a one speed transmission.

 

[dirt bike dave]

Found the specs below on a Suzuki page. It is for the 2004 model, but I don't think the bike has changed much (if at all) over the last 25 years. Spark plug info is near the bottom.

2004 SUZUKI JR50

Start the kids off right with the 2004 Suzuki JR50. The JR50 is ideal for first-time riders and makes learning to ride easy and fun for even the smallest riders. The two-stroke, air-cooled engine and single-speed automatic transmission creates the perfect learning environment for young riders. The combo allows kids to focus on riding without having to fumble with a clutch. Other convenient features on the JR50 include a heat-shielded, spark-arrester-equipped muffler and Suzuki CCI oil injection, which does away with pre-mixing fuel.

The RM-inspired graphics and Champion Yellow bodywork provide big-bike looks while the integrated seat and fuel tank allow the rider to move around while riding. A height-adjustable seat means the machine grows with the rider and ensures years of enjoyable off-road riding.

JR50 (K4) AT A GLANCE

Suggested Retail: $ 1,099.00

Engine Type: Two-stroke,air-cooled single

Bore and Stroke: 41.0 mm x 37.8 mm

Front Brake: Single Mechanical Drum

Rear Brake: Single Mechanical Drum

Dry Weight: 84 lbs. (38 kg)





2004 JR50

SPECIFICATIONS

DIMENSIONS AND DRY MASS

Overall length: 1245 mm (49.0 in.)

Overall width: 595 mm (23.4 in.)

Overall height: 730 mm (28.7 in.)

Wheelbase: 860 mm (33.9 in.)

Ground clearance: 115 mm (4.5 in.)

Dry mass: 38 kg (84 lbs.)

ENGINE

Type: 2-stroke,

1-cylinder, air cooled

Bore: 41.0 mm (1.614 in.)

Stroke: 37.8 mm (1.488 in.)

Piston displacement: 49cc (3.0 cu. in.)

Compression ratio: 5.6:1

Carburetor: Mikuni VM12SC

Air cleaner: Foam element

Starter system: Primary kick

Lubrication System: Suzuki CCI

TRANSMISSION

Clutch: Centrifugal, automatic

Transmission: Single speed 2.230 (29/13)

Primary ratio: 2.650 (53/20)

Final ratio: 2.153 (28/13)

Drive chain: 420 chain, 78 links

CHASSIS

Front suspension: Telescopic, height adjustable

Rear suspension: Twin shock, height adjustable

F. suspension stroke: 200 mm (7.9 in.)

R. wheel travel: 200 mm (7.9 in.)

Rake: 25º

Trail: 37 mm (3.4 in.)

Steering angle: 45º (right & left)

Turning radius: 1.3 m (4.3 ft.)

Front brake: Drum

Rear brake: Drum

Front tire size: 2.50-10 2PR

Rear tire size: 2.50-10 2PR

ELECTRICAL

Ignition type: CDI

Ignition timing: 24º B.T.D.C.

Spark plug: NGK BPR4HS

CAPACITIES

Fuel tank: 2.0 L (0.5 gal.)

Transmission oil: 450 ml (0.5 qt.)

 

[ellandoh]

all right fellas between this info and what the parts guy can tell me i'm pretty optimistic we can get 'er going :)
i cut the chain off today , it was rusted to the rear sprocket, and got the rear wheel rolling .

is there another type of intake for this little two stroke? besides reeds , it doesnt look like its possible to have reeds assembly where the carb goes into the head

thanks again fellas

PS i can already see the nephews are gonna learn to appreciate a steel gas tank :yikes: as i did as a kid :pissed:

 

[dirt bike dave]

Is the carb or intake off to the right side of the engine? If so, it probably has a rotary valve. This is basically a circle of metal with a slice out of it. It spins with the crank. When the window is open, the engine sucks in the intake charge. Lots of old Suzuki, Kawasaki and Can-Am two strokes used a rotary valve.

 

[Little Dinosaur]

man that was my first bike. how about send us a photo.

 

[ellandoh]

soon as i get it in action ill get a video clip :)

at the moment im trying to get spark.............well actually trying to narrow down why i DONT have spark. so far ive ruled out the ignition module