i have a 1973 volkswagen superbeetle, i had to rebuild it about a year ago and it ran ok for a month or two until i took it to a local guy that worked on them as a profession. the car ran fine for two or three months until i decided in all my brilliance to take the motor back out again to replace some of the engine tin. since then i the issue that i have been having is this…when i crank the car it runs fine until it reaches operating temp. or i get around 60-70 mph not sure which is causing the problem… after which i have a serious lack of power and the car seems like it is running out of gas…ive considered putting on a new carbuerator and someone told me that it could have been the ignition coil…any advice or ideas?
The suspect might be either the coil or the ignition condenser. These things are about impossible for the DIYer to test. The condenser is dirt cheap and easy, so try that.
If you change the ignition coil you must use a coil made for the air-cooled VW. The VW coils have a built-in resistor and the use of a regular coil will eat up the contact points pretty quick.
I’m inclined to think the problem is not related to your engine R and R unless the fuel feed line is pinched.
Also, I don’t know which sheet metal you replaced but there is one thing very critical on these engines and that is the shroud flaps.
The flaps are designed to remain closed when the engine is cold and open thermostatically as the engine warms up. As the flaps open more cooling air is blown over the cylinder heads and barrels.
If the flaps stick (not rare at all) the engine will run excessively hot, lose power, and can even barbecue itself.
Many people pry the flaps open, wire them in place, and head off a problem before it starts.
Just a few suggestions and hope some of it helps.
(That flap thing is what I would look at first since it could be fatal to the engine.)
OK,
I take it you worked on these cars back in the 70's?Yes, I worked on quite a few of these things, both at dealers and in my own shop. I’ve also owned 3 or 4 Beetles and a couple of Buses, including a hippie bus. White over red, gold flake dashboard, and the interior completely covered in deep lime green shag carpet. What an eyesore! 
It was uglier than the Morris Minor I owned that was black and had a large daisy completely covering the roof.
I used to have one about this old(30 years ago). The carb was always getting trash in it. Make sure your economizer valve is not stopped up. I think there is a plug on the bottom of the reservoir you can remove to drain out all the sediment. Be careful, gas will flow and create a hazard.
i replaced most of the engine shroud…i think that there are two or three smaller pieces that i had no clue where they went…the coil is ok i believe and im getting fuel into the carb…the carb definatly needs to be changed and i plan to get a new one in a few weeks…another thing i thought could be causing the problem would be the distributer…i changed the points and condensor and it ran fine for a few days and then started acting up again…kinda agravating
Remember that this car’s engine has an electric choke. When you took the engine out you had to disconnect the wire to it along with the hot lead to the distributor. Is it possible that you have not reconnected that wire; that you are not getting 12 volts to the choke heater element because the wire is open; or that the heater element itself is open? Is the choke open when the engine is fully warmed up?
Let us know how you solve this.
how would you check the electric choke…just use a voltmeter to measure from the connection to ground…and how would you know if it was open or not?
You can use a simple test light to verify whether the choke is receiving power or not. If there is no power at the choke a fuse could be blown.
From memory here, it seems there is an in-line fuse between the choke and coil + terminal. Should be in a black plastic holder.
Check this with the key in the RUN position.
(Also make sure the connections on the coil are clean and tight. The wire ends have a tendency to loosen and burn over time and could cause power loss to the choke.)
If you have power at the choke then allow the engine to run about 4 or 5 minutes, and with the air cleaner off, note if the choke flap is wide open. It should be. Choke heaters seldom go bad on these carbs but anything is possible.
Also make sure the choke flap moves freely.