eBay 4 million reasons you'll find it here
    We stiiiiiill had cooling problems!  I suspected the 30 PICT carburetor(used with an adapter) might be part of the problem.  The correct carb for this engine is this 34 PICT.  Our local air-cooled VW guy had a box of them, claiming that the air jets or passages would clog and he could never get them clean.  His answer is to back out the idle air jet cover screw until the car idles OK and center-punch the carb body to hold
the screw in position!  Or sell his customers a whole new carburetor.  
    Our solution was to take the idle-air jet out and clean it!  It took 15 minutes!
    This picture shows the carb after soaking in carb cleaner and cleaned in solvent.  A rebuild kit with new accelerator pump, gaskets & seals is seen in the plastic wrapping.
    Assembled and ready for install.   
    Now when our friends ask how the car is going, we quickly throw open the engine cover and do the Vanna White presentation bit towards our new carb. They just give us THAT LOOK and change the subject.
if you're not familiar with it, is the, "OK, try not to laugh" mixed with the, "I'm so glad I'm not you" and a little of the, "It's
so sad to see him/her like this, I wish there was some way I could help" looks, all mixed into one.  If you're not too lost in your, "Look at my baby, isn't she the prettiest thing you ever saw" reverie and manage to backpedal a bit, explaining that you know you're kind of crazy about this stuff, you'll get the "He/she's really weird but I still like him/her" look.  If however, you should charge right ahead and start enthusiastically pointing out the specific details you're extra-proud of you'll likely get the, "OK, now I'm getting scared" look. Not that you'd notice.
    The new carb helped.  We're fairly close now.  We can sustain a speed of about 65 mph on the hottest summer days (mid-to-high 90's) with the oil just under 225 degrees.  Propping up the front of the engine cover gets us up to 70.  We need another 5 mph.
    Anther problem developed though.  Actually it was there with the old carb to but it seemed worse with the new one.  It
seemed like we couldn't get the high idle we wanted for cold startup without also getting too much choke. While noodling over the situation we noticed that there was a little circle about 1/4" engraved on the choke flap.  Almost like there could be a hole right there...