Picked up an old air-cooled twin as a winter project

Hey everyone. Picked up an old air-cooled twin as a winter project, running but badly neglected. The carbs need balancing, the valve clearances have clearly never been touched, and I don't want to guess at torque figures on an engine this age. The dealer quoted me an eye-watering price for a printed factory service manual, assuming they can even source one at all. Where do people get proper service documentation for bikes that went out of production decades ago, and is a scanned copy good enough to work from, or is there a catch I'm not seeing?

Paying dealer prices for paper on a bike that old makes very little sense when the same document exists as a scan. Make sure you're after the factory service manual rather than the owner's handbook - the handbook won't carry torque figures or clearance specs, which is exactly what you need. ManualMachine manualmachine.com/ has a sizeable motorcycle section with full service manuals running to several hundred pages, including a lot of older Japanese twins. Check that whatever you find covers your exact year range, because clearances and carb settings often changed mid-production. And do the valves before you touch the carbs, otherwise you'll end up balancing them twice.