Which motor

[battmo]

Being kind of new to nitros, my os 50 Hyper ran lean and got real hot. looks like the head was not tight enough, but i did check every thing else. There is a hole in the piston but no scoring on the cyl. and the crankshaft hits the bottom and sides of the crankcase and left it kind of rough.Also melted some of the fan shroud. So I thought that I should get another motor, and was wondering what the helifreaks thought would be the better motor OS 50 Hyper or the YS 50.This is on a Zero-g raptor 50. This is my first post,I' v always been able to find all the info that got me this far,you guys are a lot of help THANKS.

[LAMAR COOLEY]

battmo,
Sorry to hear about your mishap.
Both engines, either the YS or OS, are great powerplants for a 50 heli.
There have also been good reports and bad on the "Redline" by T.T.
However I think it wise to try to resolve your problem about the lean run on the
OS 50.
If you haven't already done so.
It sure would be a bummer to blow another engine.
Regards

[ShinOBIWAN]

I don't think the YS50 is the equal of the OS from the reports I've read. The YS91 is a superb engine but the YS50 is nothing special.

Maybe others with experience of the YS can chip in.