I had a DP EXtra with a YS 140DZ on it and it was a wonderful combination. No trouble pulling out of a hover. I was using a APC 18x6W and getting 9800 rpm's peak. I flew at 9600 rpm's and it was a blast. Some of the advantages were the light wing loading and great throttle response. Right now the 140DZ is on a Kankge CAP @ 13.5 lbs. It will do anything I am able do. I had a OS 160FX on the DP Extra and it did not make the grade. I would skip the Moki 1.8. If I went to a Moki it would be the 2.1 as there is very little difference in weight so you might as well get the extra power. BTW if you go to a Moki give it a great deal of break in after that it will be a very good engine.