Running Rich w/Points?

[vamram]

I've been running my '74 Super w/points for almost 6k miles now, since the compufire knock-off module died a year ago. It's a stockish 1600dp, running a Volkzbitz rebuilt Solex 34-3, and a 205AN distributor. Points are good w/only about 1k miles on this set (swapped the dizzy out about 1k miles ago), gap a perfect .016. W/this combo, I've had to adjust the carb pretty rich - the volume screw about 5+ turns out. The 205AN also advances fine, about 42* at full advance w/the advance vacuum hose connected. Plugs looked ok on the electrode, sooty on the edge.

I decided to swap out the distributor and replaced it w/a 205C I purchased rebuilt from one of the great Samba rebuilders. I installed a new Hot Spark ignition module instead of points, timed it to 29-30* at 3.4k rpm, vacuum port plugged on the carb. This settled in at idle to a textbook perfect 7.5* BTDC.

Curiously, the carb tuning changed completely after swapping out the distributor. Following the procedure of starting out at 2.5 turns out for both the volume and idle screws, the fully adjusted volume screw w/this combination is out only 3 full turns. I don't remember where the idle screw ended up, maybe 1.75.

I don't really understand the workings here. Can someone explain how changing the distributor and going from the 205AN w/points to the 205C w/the Hot Spark would allow me to tune the carb significantly leaner? Also, max advance w/the 205C, vacuum hose connected, is about 36*. That's 6* less advance than the 205AN and must be the vac can, right?

Thanks,

Victor
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'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
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Save the Supers!!

[VW_Jimbo]

Victor, I don’t know anything about the Hot Spark system. But here is my quick theory. Duration. The total time of spark build up and firing is so much more efficiently controlled, by the module. The silicon chip is smarter than the mass of steel running around in circles (with worn lobes) pushes the other piece of steel. It is called advancement, not in timing, but in the technology that controls it! And it is a good thing! Technology has lead to all kinds of efficiencies. My best example would be running water and the sewer system. Both advanced society by a large degree. Sorry for the pun!
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[vamram]

Thanks for your reply Jimbo!
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!