But I need help , I am working on my sons 1966 BMW , runs well above 1500 RPM but idles like crap high compression in all cylinders but extremely low vacuum ,the plug foul quickly with a black soot. We assembled the engine I am leaning towards late valve timing I may have installed the timing chain one tooth off. . Any ideas would be welcome I have spent  all day and everything seems correct but something is wrong. 

If it's anything like US car the low vacuum is letting the power valve in the carb stay open which would account for the plugs loading up at idle. It's been my experience  to observe low compression with a retarded cam.

A cranking compression test on all the cylinders could potentially provide some insight.  Higher than normal would be indicative of advanced cam timing.

A quick non-instrument check of the camshaft timing is performed by observing that the rocker arms on a given cylinder at TDC (during the overlap cycle) are equally open.  If either of the valves is open much more than the other, then the cam timing being off would be high on the list.  A slipped damper ring would need to be ruled out in this instance.  If it’s the intake valve that’s open considerably more than the exhaust, then the cam timing would be overly advanced.  If the exhaust valve is open more, then the cam timing is retarded.

Lorena, Texas (South of Waco)

The title says Mercedes.  1966 BMW is indicated in the thread.  BMW also make motorcycles (motorcycles came first, in fact).  Which / what is it?


Lawrenceville, GA

Charlie.  That was my 'bad'. The title originally was simply 'Way off topic' and I added the extra for clarification.  It's fixed now.

Lorena, Texas (South of Waco)

So I can just pull the valve cover and watch the cam shaft open an close the valves . Almost sounds to easy Thanks Ted I will take a look

The best solution is to get  him a  54-59 Ford.  From my limited experience with Beemers, they are the worst and most expensive cars to own.  That's why most people lease them


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Not sure if you can lease a 1966 BMW 2000cs  I think if you do a web search you will see the quality in the early BMWs this car has a lot of very nice appointments. Besides he thinks my 1955 Glass Top is an old mans car