1966 BMW R69S Restoration: January 1999 [page 2]

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1999 January 20 (Wednesday)

It is time to start opening this thing up. I went through the paperwork that came with the bike and see that the cylinders were bored to 2nd over size and an “unleaded” conversion was done to the heads. This occurred in Feb ‘93. Don’t know how many miles ago that was, but I don’t suspect too many.

Cylinder head removal
Cluttered garage

Cluttered garage

Cluttered garage
Engine on work table

Engine on work table

Engine on work table
Ready to remove valve cover

Ready to remove valve cover

Ready to remove valve cover

The garage was a mess. After moving the frame out of the way I sat the engine on a short stand/table so I could sit on a little work stool and work in relative comfort. The third picture shows me ready to pull the cylinder heads.

valve cover removed

valve cover removed

valve cover removed
Exhaust rocker removed

Exhaust rocker removed

Exhaust rocker removed

I removed the valve cover for the left cylinder and noted that new valve covers gaskets are needed. The four bolt holding the rocker arm assemblies were removed followed by the the lower head bolt and the upper head bolt. The head came off easily. The head gasket looks new. I’ll keep them as spares.

Left head removed

Left head removed

Left head removed
Head removed (different angle)

Head removed (different angle)

Head removed (different angle)
Left cylinder head

Left cylinder head

Left cylinder head

Pictures of the left cylinder and the cylinder head components.

Right cylinder head

Right cylinder head

Right cylinder head

I rotated the engine 180 degrees to pull the right cylinder head. This is the cylinder that was noisy. One interesting thing is that my 1/2 drive 14 mm socket wouldn’t fit through the opening in the fins to access the lower cylinder screw. The same socket fit on the left cylinder head. I used a 3/8 drive 14 mm socket on this side as it had a smaller outside diameter.

Rocker arm assembly
Rocker arm assembly

Rocker arm assembly

Rocker arm assembly
Rocker assembly in parts

Rocker assembly in parts

Rocker assembly in parts
Rocker assembly for storage

Rocker assembly for storage

Rocker assembly for storage

When I pulled the exhaust rocker arm assembly from the right cylinder head it practically fell apart in my hand. The first picture shows two of the needle bearings that fell out. I pulled the unit completely apart to ensure I had all 34 needles. When I put it back together I used cable ties hold the assembly together for storage. I need to find out what the proper fix is. I suspect that this was at least part of the reason why the right cylinder was so noisy.

Now that the cylinder heads are off pull the cylinders and remove the pistons.

Right cylinder
Ready to remove cylinder

Ready to remove cylinder

Ready to remove cylinder
Right cylinder removed

Right cylinder removed

Right cylinder removed

I removed the right cylinder and put a bit of stiff cardboard around the connecting rod so it doesn’t bounce on the case. Marks on the case tell me that previous disassemblers weren’t so careful.

Right piston
Right piston removed

Right piston removed

Right piston removed
Removed parts

Removed parts

Removed parts

I removed the snap-ring from one side of the piston and pushed the wrist-pin out with wooden drift whittled from an old broomstick handle. Heat was not needed for this side.

Left cylinder and piston
Left cylinder

Left cylinder

Left cylinder
Left cylinder/piston removed

Left cylinder/piston removed

Left cylinder/piston removed

The left cylinder came off as easy as the right. The wrist-pin, however, was harder. I removed a snap-ring and found that the wrist-pin would move in the piston (without heat) but seemed stuck to the connecting rod. I removed the other snap-ring. The wrist-pin didn’t want to go in that direction, either. Finally some heat aimed at the little end of the connecting rod and some gentle taps with my wooden drift got the wrist-pin to move.

 

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