Thumbnail Filmstrip of Hilborn #61 Rotator Spool- Largest Spool that fits Images
#61 spool takes the place of a #56 spool
This fits all Hilborn barrel (metering) valves that accept a 23-54-56-77 spool
Has sharp idle ramp for engines when using a small amount of nitro or a very large 575-700 cu in Alky engine
Provides for more fuel in first 30 degrees of spool rotation.