Anybody know of a - in stock - replacement or substitution for the discontinued turnigy 2730 1500kv motor. Have been using these on 1/2a airplanes

Try this, Use either the 1300 or 1700 motor  With more info like John says I may be able to suggest more substitutes I tend to go up in kv when in doubt but with more info I could advise better  https://www.banggood.com/Racerstar-D2730-1300KV-1700KV-3000KV-2-3S-Brushless-Motor-for-Fixed-Wing-RC-Airplane-p-1642554.html?rmmds=search&ID=519231&cur_warehouse=CN

What are you using it on? I was thinking of trying a half a type plane?

800ma 3S
6X4 7X3

Thanks for the help...

I like Cobra motors.   It looks like the Cobra C2204/40 is the correct size for a 3S battery and a 6x4 prop.  According to the Cobra prop chart @ 11 volts, (3S), the APC 6x4E prop will draw 6.98 amps and turn 13K RPMs.  If my math is correct this should give 5 minute runs.

https://innov8tivedesigns.com/cobra-c-2204-40-brushless-motor-kv-1570.html

Haven't tried one but the Cobra prop chart seems to be accurate so it should work.  Cost is 22$ or so.  Don't know if this is the price range you are looking for but Cobra motors are solid.