With the help of an old Aermacchi friend I found the reason why the bike spit oil out of the exhaust. The fitting (oil inlet) on the cylinder was defective and over time 2- Stroke oil flooded the crankcase simply by beeing parked in the garage. The fitting has an integrated back pressure valve. I replaced the oil-line fitting and removed the excessive oil from the crankcase and from the exhaust and since then the bike runs good again after spreading the remaining oil everywhere in my driveway out of the exhaust.

Bike runs good but still smokes too much from the exhaust when the engine is cold. Also some oil / gasoline mix comes out of the exhaust.
I checked the carb and wrote down the jet settings in case I have the experiment a bit there:

Starting jet: 70
Main jet: 100
Low speed jet: 55

I am currently writing an article for a “classic motorcycle” magazine in Germany about the SX-175. Today I took the bike for a little spin and a photoshooting for that article.

Just a comparison of the bike before and after the restoration.

The bike is finally complete and was running for the first time a few days ago. The carb needs some adjustments, but overall it looks good.

Yeah, I am almost there. Only the accelerator cable and the gas line are missing and then it’s done.

• After rewiring the whole motorcycle I had a strange problem and only had a spark with the ignition switch beeing in the “off” position. As soon as I turned the ignition switch to “ignition” or “ignition & light” I had no spark anymore. After some try & error and asking Michael from the UK for help I learend there is a different between switches for 1974 models and switches for 1975 and later models. To be more specific, I was always aware there is two different versions of the switch: One version with the pattern: “park – off – ignition – ignition/light” and  one version with the pattern “off – ignition – ignition/light – park”. What I didn’t know: One version connects the pins 6-7 when “off”, while the other version disconnects the pins “6-7” when beeing in the off position. All other functions are the exact same between the switches. Thankfully Bram & Jenny from Luxembourg helped me out with the correct ignition switch! Thank you!
• On the first picture you can see a 1973/74 version and a 1975 & later version of the ignition switches
• On the second picture you can see my brand new wiring harness connected to the ignition switch.

A litte life sign. Haven’t done much work on the bike lately but I am progressing slowly with the wireing harness.