Sunday, May 20, 2018
Spartan Rock n' Roll; 50+mph, 6s Brushless, Howling Fury on the Water
Home » News » O.S. Speed 21XZ-B Spec III

O.S. Speed 21XZ-B Spec III


The 21XZ-B Spec III is the evolution of a proven powerhouse that has been a winner at numerous races worldwide. With upgrades that enhance its performance and drivability you’ll hear the difference in the engine’s roar when warming it up. Once you’ve experienced the speed and power of the Spec III, you’ll be on the fast track to the winner’s circle!’

Features – 

Long stroke engine provides more torque
Enhanced low-to middle-range torque provides a great advantage on tracks that require lots of power
The newly developed cylinder liner features 3 scavenger ports and 3 exhaust ports, and works with the crankcase to deliver more power with less fuel consumption
The drop-in type outer head is now lighter, with a lower CG
Silicon-potted, DLC-coated crankshaft with pressed-in tungsten weights
Easy-to-tune 21J carburetor with 6.5 mm restrictor

Click here for more info – 

Leave a Reply

Your email address will not be published. Required fields are marked *