from a 1971 280SE, M130.98. Unlike the M130.92, it does not have a vacuum retard port on the diaphram module.

When I observe how far the advance rotates (by pushing on the plate), it is twice the advance range of the carburetor version, M130.92. The carb version is restrained by the limit of the 'arm'.

I tried to swap the advance diaphrams on the 2 distributors, but the mounting plate screws don't line up.

Right now, I don't think I am getting any vacuum advance from the 3 way valve. I WILL TRY 250_COUPE'S METHOD, AS OUTLINED BELOW:

On my 250C, I disconnected the three-way valve completely and routed the vacuum line straight to the advance side of the dizzy. There is only 4 degrees of advance in these dizzys but I figured some is better than none. I set the timing at 40-42 degrees at whatever RPM the book called for.

And futher explained by Arthur Dalton:

The idea is to set the 3000 rpm timing as that is at the top end of the mechnical advance . If there is a 20 degree mechanical advance , then when at idle rpms, the car will be at 10 BTDC... but if you have manifold vac and bring this to the retard section of the vac device , when the carbs are closed , the vac retard will bring the idle timing down closer to TDC .But, as soon as you open the throttle, the retard will collapse and you will get advance. So, this gives you are steady idle at around TDC , about 10 degrees off idle , and full advance at 3K

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1970 280S M130 engine- good runner
1971 250 M130 engine- #2 rod bearing, gone
1971 280SE (blown engine,parts car)
1977 German 280S W116-only 33 years old