PeachParts Mercedes-Benz Forum - View Single Post

G-Benz · #2 01-04-2005, 10:41 AM

You can still run the old gas...the octane content isn't what breaks down.

If there is 4 yr. old gas sitting in the carb float bowl, that is where your real potential for problems will lie. Old gas "varnishes" and penetrates jets, butterfly valves, accelerator diaphrams and so forth. If you can get it started at all, I suggest filling up with fresh fuel of course, and probably the highest octane you can find. You did say you had injectors, so it may be a moot issue. My dad has a 71 280 SE and it's a carb unit, so I had to mention this.

I left a VW sitting for 5 years, and ultimately had to rebuild the carbs.

Something else you noted is that it is a 1970. Cars of that era where designed to burn leaded fuel. The lead content served as lubricant to valve seats. Engines designed to burn unleaded are equipped with hardened seats as a result. Over time, your engine will suffer from valve seat recession, requiring a complete valve replacement as a result of prolonged burning of unleaded gasoline.

My same VW motor was rebuilt with hardened stainless steel valves in order to be able to burn unleaded gas.

This post was not meant to scare you, but alert you of potential problems you may encounter...