Painting engine Yamaha RD125

While the engine was still apart it was a time for some engine painting. The outer engine cases are a kind of satin black with polished aluminum stripes, the engine barrels and heads are also satin black while the top edges of the fins are also bare aluminum.

Yamaha RD125 A engine before painting

First I used paint stripper to get rid of the last parts of the original paint.
After rinsing with water I sanded the parts with 400 grit. If yo use finer grit the paint won't stick very well.

The cylinder barrels and heads are pretty hard to clean so I used a simple sandblast gun. Sand blasting will also give the paint something to bite in.

Cylinder heads Yamaha RD125 before and after sandblasting

The outer sides of the cylinder heads are bare polished aluminum and it's easier to polish them before painting.

Before I hit the outer cases with engine primer (heat resistant) I cleaned them with wax and grease remover.
After some online research I bought VHT satin black caliper paint and engine primer. Caliper paint is even more heat resistant then engine paint and the satin black colour is really close to the original colour.

VHT caliper paint and VHT Engine primer

3 coats of Engine primer

After 3 coats of VHT satin black caliper paint

In the close up you can see some light orange peel but it looks nice in real live ;)
As you also can see I didn't mask the stripes but used a razor blade, sandpaper and aluminum polish to bring the "silver" stripes back. Same for the top of the barrel and head fins edges.

Left engine case Yamaha RD125A

Left engine case Yamaha RD125A

Right engine case Yamaha RD125 A 1974

Left engine barrel Yamaha RD125A

Cylinder head Yamaha RD125A

In order to make the paint chemical resistant you have to bake it in an oven, but as some of the parts have plastic or rubber components I will "bake" them while running in the engine. I only have to be really careful with petrol before it's all baked...