Troubleshooting a dual-vacuum distributor

[fortyeye]

OK I have a very similar problem. I have a 75 fuelie with dvda distributor. The canister has gone out, so the VW mechanic in my area set the timing to match an svda but now the thing overheats all the time. So, I'm not sure what to do here. Do I switch to an svda, buy a canister I'm at a loss.

As Marc stated in the original post above, if you can find a good DVDA advance/retard can for your distributor that costs less than a new SVDA, you can keep your present unit and just repair it. SVDA distributors have increased in price since this thread started (2004) but are still available from a variety of sources. John at aircooled.net has his own SVDA http://vwparts.aircooled.net/Aircooled- ... n-svda.htm
works quite well and John stands behind his products (his unit utilizes his own curve / spring setup). Not the cheapest, but a quality unit for sure. Check around and read up on other peoples experiences.

[wildthings]

Make sure that the centrifugal advance is working correctly. You should be able to turn the rotor clockwise 10° or so and have it spring back. There is a felt pad under the rotor that needs a few drops of oil every 5-10,000 miles, the oil serves to lubricate the centrifugal advance unit so make sure this has been done.

To time your engine, pull both vacuum hoses off the distributor and rev the engine up to 3500+ rpm until the timing mark doesn't advance anymore. Your timing at this point should be in the 28-30° range.