ORIGINAL: DiscoWings
OS 160 makes more power than the ys 140,
But YS 140 would be better overall engine because of wider power band and it is naturally pumped...Many people like having the fuel tank at the CG so that is a nice bonus...By the time you buy a muffler and a pump for the OS 160 its cost is about the same as a ys140
I just sold my YS110 because I don't like the price of high nitro fuel.
There is nothing narrow about the power band of the OS160--with the right prop spool is instantaneous(Skorepa 18x6). It does need a pump and proper adjustment to get it metering decent thru the entire range of the motor & fast spool.
You might find this interesting....
OS 1.60 v.s. YS 1.40 DZ Cost Analysis -
http://www.rcaerobats.net/MotorCostComparison.htm
Notice the fuel usage between the two motors on the same pattern plane flying the same sequence? The OS is much less to operate.
I like YS's though...just cost a lot more to run one. And not worth it to me.