Quick note/update on my GP 1/4 scale RV-4. Found the issue with idle (at least the immediately apparent one) in my throttle linkage not being up to snuff. A little slop goes a long way when the low end throttle accuracy is as critical as it is on the DLE-20! Might be the only engine I've ever run across that could benefit from a digital servo!
Now that i have direct/straight metal rod (not to worry, ball link is nylon) there is almost no play in the linkage and I expect better repeatability on my throttle positioning. Also dropped from the stock (I think 14 ounce) tank to an 8 oz so will haul less excess weight with a full tank of gas. Hopefully the rain will stop sometime this month and I can get another flight or two in and report back further on performance versus my old Saito 125 and suitability for this aircraft.
Hope to pick up a couple more props down at the Nall to try out on this combo as well. RPMs so far seem appropriate so staying with a 17x6 is my first thought... just looking for a Xoar laminate and a Vess to see what differences those make... Maybe I could try a 16x8 and hope for a bit more speed as the only thing I've noticed so far is that looping requires hoarding some energy and gets very slow at the top if I make it very large (which I think is appropriate for this airplane).
Wouldn't mind to try a 16x6 or 16x8 but the 16x6 would unload it a bit and not sure I want to go there. Need to double check what the max recommended RPMs are as I'm already at 8500 so unloading much further makes me bit nervous. Don't want to overrev and cause an issue.