Update regarding the 750 with the hammered valve stems:
Yesterday at noon I started to revive the patient together with Alex the owner and Reinhold alias "Pilot" in an very old ex. wagon factory.
We have renewed valves, valve springs, camshaft (7/1) and the rocker arm including screws.
It was very easy to do with the hot/cold method:
1. step - camshaft in freezer, bearing in the oven => mount both
2. step- camshaft incl. bearing in the freezer, head in the oven
- assemble each - done
In addition, it is particularly important to have a good connection to the housewife so that you can "abuse" the stove and freezer.
Then it went on with the piston pin bearings, which were extremely worn. A madman had once pressed them in with brute force and left deep marks. With our method, changing the bearings is very quick and very accurate. We wiped the game of the bolts down to +/- 0.
Then the pistons got new piston rings (80.0) and the cylinder liners were only minimally honored.
On the occasion we increased the cylinder capacity from 750 ccm to 2 x 0.5 liters = 1000 ccm = (see picture
).
When assembling the engine with a new camshaft chain, we installed wire brackets in the top of the head so that the oil supply is secured in the upper horizontal oil channels that lubricate the camshafts.
When installing the motor, the correct fine-thread screws were finally used. When adjusting the valve clearance and the ignition, we found that the TDC markings on the freewheel were not correct - it was loose and the wedge in the crankshaft had sheared off.
At 5 o'clock in the morning we were finished with the work and the installation after about 17 nonstop hours.
It was a great action in a great location with good blues music (thanks to STAR FM "Blues") and nice friends.
The "Black LAVERDA" is a wonderful bike.
Thomas aus LAU