There are a million different ways to break in but they boil down to 2 ways, heat cycle or idling a few tanks and running rich and gentle.
As you dont like heat cycling just idle a few tanks, then drive it rich at half to three quarter throttle for a further 4-5 tanks then start tuning a little.
How did you tune your savage? its no different just because its in a buggy.
I always heat cycle but I'm sure there will be instructions with the engine/buggy