Almost ready for splitting the engine.

Now tool for my Aermacchi-tool-collection. 🙂

Before disassembling. Rear wheel bearings: SKF 6204-2RS1

I built myself a pinion gear puller that worked good. As you can see on the last picture the piston rings are totally baked into the piston.

The inside of the engine looks not very good at all. Spark advance is broken and the primary gear is totally worn out. I am pretty sure more bad surprises will come, going deeper into the engine. I also noticed that the left engine cover has a 1971 production time stamp and the right side a 1968. I am pretty sure someone had the engine disassembled before me.

The engine is the so called “ashtray head”. The cylinder and head are designed for the US market. It replaced the earlier, classic Aermacchi cylinder/head. Customers in Europe didn’t like that design much and so it was available in Europe just for a short time period from 1969 to 1970 before they changed back to the classic knucklehead with the 1971 models. In US they kept the ashtray design until the arrival of the 1973 model of the Harley-Davidson Sprint.

Engine crankcase: L988