http://www3.towerhobbies.com/cgi-bin/wt ... XBY42&P=ML
There is a thread on RC universe that talks about a replacement...the OS 25 fx ii:
http://www.rcuniverse.com/forum/rc-comb ... fx-ii.html
Looking on Amazon they list one for only $460

https://www.amazon.com/OS-Engine-MAX-25 ... B06WLGR2GM
Anybody have any info? I replaced a piston & sleeve on a tired OS 25 fx for NATS that blew some fresh air into the engine, and still have a few new ones on the shelf.
This "slimer" at heart may be forced to switch to "E-power" eventually!
Thanks for any info,