Good morning RC, We are sitting around the Flying Field shooting the breeze between Saito talk.
Pete, few people knew that MAICO made road bikes. This one is a 250 that is made out of the 125 crankcase. It has the 54mm stroke of the 125 and the 76mm bore of the 400. Top speed 99. The 125 was 54x54mm. The 490 is regarded by most experts as the best open class motocrosser ever built. Still is. The 125 was a rotary valve engine, the carb is just inside the side cover by the brake pedal, the air filter is up under the seat hence the big fat pipe coming down.
Most people seem to under prop the 1.25 Saito, it's a 9,000 rpm engine so you might as well prop it that way. Some engines like to grunt.
http://www.motorcyclespecs.co.za/mod...20MD%20250.htm
You can read some MAICO specs here.