Furter, can you post the type (second block of numbers, between the model and code blocks) and pictures of the carburetor and linkage please? At present I can't find a specific setup for a horizontal crankshaft 80000 engine in the manual, but may be more successful with more information.
Also, can you post a picture or description of where the numbers are on your engine please? That may help jackg.
If your chains are correctly installed, they are severely worn and need to be replaced. Taking links out just enables you to keep using out-of-pitch chains long enough for them to destroy the sprockets. Why not post a picture of them, so we can try to figure out whether the installation is correct, before you go to the expense of replacing them?
