Jensen 65 Model Steam EngineFull featured, mid sized, Double acting slide valve stationary cylinder, "dry fueled engine with a 2 1 8 x 6 boiler. Powers Erector Sets and other miniatures with power to spare also spin start" reversible. Includes pop valve, whistle and throttle. Bore: 7 16" x 5 8" Stroke. Note: All fuel fired Jensen steam engine fireboxes discolor after FIRST use. They are NOT painted with high temperature paint or powder coating. Click on picture for large view.