Hello Max Rackstraw,

If You have the time, You should take out the engine of the chassis. Take out the Air Filter and Manifold/Pipe, and close all the holes including the Fuel Nipple. Clean the exterior of the engine thoroughly. Then take out the Back Plate and put tissue/napkin on the lower side of the crankcase while tilting back the engine to absorb any fuel left on the crankcase. Then put some drops of After Run Oil and put back the Back Plate. You could store it inside a Zip Lock bag to further protect it.

A while ago I like to use TAMIYA Engine Treatment spray, it is the best product to avoid rust!!! But sadly it is not available anymore. I've been trying to spray WD-40 seems to be OK so far.

Cheers..