Working On Dave's RD400

I spent the day working on rebuilding the engine for a Yamaha RD400 of a co-worker's from work. We got quite a bit of it done, but the pistons and cylinders still need to be installed.



Here's the frame, all painted up and carefully reassembled, waiting for me to finish the motor.



Dave has been working on this bike for quite some time, meticulously restoring this RD to near-pristine condition.



We started by laying the crankshaft in place in the lower half of the engine case.



Next, the transmission and shift fork assemblies were set into place. After this, all of the rubber seals were installed.



The bottom section of the engine case was put aside on this tray while we went to work on the upper case.



We had to rework the studs, install some of the hardware and a couple of seals before we could assemble the two halves.



So, the upper and lower sections have been mated, and now we're working on the drive-end side of the motor. Assembly of the shifting mechanism and clutch now had to be done.



At this point, the bottom-end of the motor has been assembled and it is time to focus on the right-hand engine cover. But first, let's take a 'tour' around the motor.



This is the front of the engine and the bolts sticking up are for the cylinders and pistons to drop into place.



From this view, you can see the connecting rods for the pistons. These are new performance pieces that will enhance the durability of the reciprocating assembly.



Ah, the side covers. Nicely painted, these practically shine like gems. Unfortunately, the paint was sprayed down into the kick starter shaft bore and the cover wouldn't slide down the kick starter shaft. Dave had to sand out the paint in the boss for the shaft so the kick starter would turn smoothly after the cover was installed.



After the bottom-end is finally put together, then we'll assemble the top-end. Here are the parts, all cleaned up and ready to go.