I had purchased an SK 70 rc aircraft engine, new, in the box at a swap meet. I installed it in a Tiger 60 and attempted the break in and it ran like crap. Stopping completely at certain rpm levels. I ran at least 4 tanks of fuel through it and finally gave up. So, I swapped the engine out for an OS 61FX which runs well. When I installed the 61 I noticed how out of balance the plane was, now very tail heavy. I had to add 5 ounces of weight to get the balance correct! I know the SK 70 is a bigger engine but not that much heavier! I don't have any specs on the SK. and can't find anything online. Does anyone know the weight of the SK70 vrs the OS 61
FX?