MAICO Pictures 1981

1981 MAICO 490 & 250. Technical specifications at the bottom of page

Since MAICO had the best machinery in 1980, their task to build the best open classer for the 1981 season was pretty simple. Flatten out the seating area, bore it out to a full sized 490 and fix the spokes. The 490 was by far the best in it's time and is still considered the best open class bike ever.

Note the redesigned side panels, the -81 also had the Corte Cosso rear shocks but most riders equipped their irons with Ohlin piggybacks or FOX air-shocks. The other obvious change is that the front of the seat is raised sacrificing the lower seat height for greater ergonomics.

The rough casting on the engine, forward mounted rear shocks and bulky fork made the 490 look mean. Even though the breaks looks fragile they provided good stopping power compared to most bikes. The swingarm was streched compared to the 1980 model

1981 250cc sweety

The 250cc model was identical except the cylinder, head, piston and the gears. It had the same balance and remarkable suspension but lacked a few horsepowers compared to the fastest japanese bikes. It was still a competitive package with smooth tractable power and maicos famous slick shifting. Note that from 1981 the 250cc model got a reed intake valve. One popular fix was to use the Honda CR250 intake. It was shorter and offered a better response.

Technical specifications MAICO 250cc MAICO 400cc MAICO 490cc
2-stroke single cylinder piston port air cooled
Displacement: 247cc 386cc 488cc
Bore/Stroke: 67 x 70mm 77 x 83mm 86.5 x 83mm
Compression ratio:
Bing V54/II ø 38mm
Bing V54/II ø 40mm
Horespower: 40HP/8000RPM (DIN) 47HP/7000RPM (DIN) 53HP/7000RPM (DIN)
Wet multi disk, 6 sintered and 6 steel plates (12), spring washers
Primary drive:
3/8 x 7/32" two single row chains, 52 links
5 speed
Gear ratio: 2.25/1.80/1.44/1.20/1.00
Air filter:
Motoplat electronic
Double loop, backbone box chrome moly steel
ø42mm Hydraulic air assisted conventional fork. 12.2" (310mm) travel
Fork oil:
570cc, 5w hydraulic oil
Rear suspension:
Steel swingarm on needle bearings. Corte Cosso reservoir shocks. 12.2" (310mm)
Front brake:
Drum brake, ø5.3" (135mm)
Rear brake:
Drum brake, ø6.2" (158mm)
60" ( 1525mm)
Ground clearance:
14.2" (361mm)
Seat height:
37.8" (960mm)
Dry weight: 218Ibs (99Kg) 222Ibs (101Kg) 224Ibs (102Kg)