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Feb 6, 2004
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Found some F21-8W Econoject motors cheap (13.99 for a 2 pack) at the local Hobby Lobby. I know these are older motors, but will they still be good? Also picked up a pack of Aerotech igniters for $3.00 and some igniter clips for $2.30. I basically bought them out of their remaining Aerotech stock. :D I think the F21-8W would be good in my wifes Mustang, but don't want to use them on it if they may be bad and possibly cato or have a bad ejection. Let me know your thoughts.

those motors are great and there is no reason they should be bad, I have some F21s from a while back and the ones I used were fine. AP motors will only oxidize over time making them harder to light, but this will not cause a CATO

BTW they will give the mustang an awesome ride
The eight second delay may be a bit long for the Mustang, especially since Aerotech delays tend to burn on the long side... The F21-8W is great for rockets like the Estes Eliminator :).
maybe a little long but I think it would be okay

I plan to fly my eliminator on that motor....bye bye
I too think you'll be ok with the 8 sec with that bird, it will be a little long, but the 6 is a little early according to WRASP...

Either way it's a tough bird and the stock shock cord is wide enough i think you'll be ok with a little bit of a high speed deployment..

I looked over the flight logs on EMRR and found plenty of flights with this bird on F20-7's and F22-7's and they look to work fine.

The only flight with an F21-8 was mine and it worked fine being a second or so late but no damage..
I've flown my 'Stang on 8's plenty of times with no ill effects. It's sturdy enough to handle some speed, if ejection is late, being a fairly light rocket.
True, the shockcord is wide, and the body tube is tough so this should take the shock....we wanna see some pics of the flight though
I figured the F21-8w would be OK for the Mustang since they seem to be pretty tuff and it recommends an F20-7w. If nothing else, I will fly them on some other rocket, as I can't pass up a bargain. I have a 7oz. scratch built that is just itching for a bigger motor than an Estes E9-8. It was built out of scrap parts, so no big deal if it is lost or trashed. :D