While I have no plans to change from my A-65, I am curious to hear about the trade-offs of going with a bigger engine in the L-2. My A-65 does okay with just me aboard and still manages about 400fpm climb with two crew.
My plane has had both the 75 and 85hp engines during its lifetime but only the 65 during my ownership. Certainly not a spritely performer but it manages just fine for putting around the local area.
I'm curious about what's left for payload after installing 90/100hp engines with electrical systems? Also range? Are you left with a single-seater good for about 90 minutes of flying?