Genuine Thunder Tiger back plate set for the PRO-21 and PRO-28BX nitro car engines. Machined from aluminium with a factory-installed brass bushing at its centre, this is the rear crankcase cover that supports the engine's starting shaft — the arrangement that lets these engines spin up from a hand-held starter rather than a pull cord. Supplied with the four 2x9.5mm cap head screws that secure it.

The bushed centre bore is the working surface here, and the reason a back plate becomes a replacement item: the brass bushing wears with every start, and a sloppy bushing lets the starting shaft wobble, chews its engagement, and can weep fuel past the rear of the engine. A plate that's been distorted by over-tightening, or scarred where a starting shaft let go, is also a source of the air leaks that make a nitro engine impossible to tune.

Fit with a fresh backplate gasket on clean, flat mating surfaces, and tighten the four screws evenly in a cross pattern rather than one at a time — aluminium plates distort easily under uneven torque, and a warped plate leaks. Fresh screws are in the packet, so there's no reusing rounded originals.

Specifications

Brand: Thunder Tiger
Part number: PN0257
Type: Back plate set
Material: Aluminium, brass bushing (factory fitted)
Includes: Back plate, 4 x 2x9.5mm cap head screws
Suits: Thunder Tiger PRO-21, PRO-28BX