• Same mounting as the YS91 making it easy to add more power to the existing helicopter
• Proven factory preset regulator for a consistant, reliable operation
• Steel lined back plate to minimize drag resulting in increased horsepower
• Larger cylinder head for better cooling
This engine ran great from the first time I started it. Tuned it according to the instructions and it makes awesome power and has a good steady idle. 4th time out, 5th gal of 20% nitro and my Hatori pipe cracked in two at the weld and around the inlet. I think it was a faulty seam, engine seems very smooth for a 120. Pulled back plate and rear bearing is rusty. All my OS and YS engines do this regardless of after-run oil. I am replacing with SS Brg.s. Overall I am very happy with the way it starts, idles and performs.