71 Beetle,Need Your Thoughts?Please...

[Lindacars]

I bought a 1971 VW Beetle from a friend of mine that lives out of state.
I drove 3000 miles round trip to pick it up and now here in North Dakota it sits outside where I am finally able to get to it with all the snow gone and not freezing as it has been since I got it a few months ago.
They had a lot of work done to it and I was told that it worked good except it started making back firing sounds and they were told the carburator needed cleaning and something about a spring on it might of came off. This VW has a 1600 Daul Port Engine. I have several books and want to know came I just take the carurator off and clean it and is it a big job. I haven't worked on VW yet but I sure am willing to try anything and now I have a VW I would love to learn as much as possible about him, I named him "Gizmo" and I can't wait till I can start driving him around.
If anyone has any thoughts of what the first things I should do or know PLEASE let me know.
Thanks for any reply...
Linda

[Liquid_89]

Well all i can think of is to get it checked out again.i don't think it would be your carburator but you never know.I meen why they didn't get it fixed when they thought they knew the problem is wierd i meen i would have.But i don't think it's your carburator.

[Gunngee]

I really don't think it is your carb. Most of the time when it's backfiring it means timing. Is it backfiring up the carb or out the exhaust???

[mechy1barry]

a quick checkup is needed,check the dizzy cap and rotor for cracks and tracking,are the ign leads o/k?are they on the correct way?what are the spark plugs like? are connections on the coil secure?air leaks on the manifolds are common.points (breaker gap) should be checked on all 4 lobes,wiring in dizzy also comes to mind.lastly poor supply from ign switch.enough for now?good luck!p.s-fuel starvation.

[kelwa1]

Originally Posted by mechy1barry

a quick checkup is needed,check the dizzy cap and rotor for cracks and tracking,are the ign leads o/k?are they on the correct way?what are the spark plugs like? are connections on the coil secure?air leaks on the manifolds are common.points (breaker gap) should be checked on all 4 lobes,wiring in dizzy also comes to mind.lastly poor supply from ign switch.enough for now?good luck!p.s-fuel starvation.

Not just fuel starvation, check to see if the fuel is any good, sounds like it sat up for a while. Smell it, if it doesn't smell like gas should, get rid of it and get some fresh fuel. Replace ALL of your rubber fuel lines, front and rear and the inline fuel filter. If you replace your plugs, and you still have bad fuel, you'll end up fouling your new plugs with a quickness.
Also see if your battery is good, if voltmeter registers below 13 volts, your battery may not have enough starting power. Any brand new 12 volt battery should register 13.5 to 14 volts.

[Doug Rodrigues]

You sure it's a backfire? May it be a popping sound? The 1968 through 1972 Volkswagens had defective crankcases that caused the head studs to pull from the crankcase. You could remove the case threads from the head studs like unwinding a spring from the studs. The condition is known as "Loose Heads." If this is your actual problem, the only cure is to install case inserts to properly anchor the head studs into the case.

If the problem is backfiring through the carburetor, it could be timing or too lean of a mixture. The timing misfiring could be something as simple as a carbon track inside the distributor cap that causes one plug wire to arc to the wrong plug wire. Take the distributor cap off and look at it. do you see anything that looks like a "line," or what appears to be a dirty cap? If so, wash it out with soap and water, dry it and reinstall the cap. Also check the spark plug connectors with an Ohm Meter. They should have 1000 ohms resistance. Same thing with the distributor rotor, although I think that the rotor should have 5000 ohms resistance. Too much resistance at the plug connectors can cause old wires to arc. At night, very old spark plug wires actually can be seen in the darkness with a slight glow as the plugs fire. If that's the case, replace the wires.

If the timing is correct, and the electrical is correct, then the only other option is to "boil-out" the carburetor. You can get a can of soaking solution with a parts basket for about $15 from PepBoys. You'll also have to buy a "carburetor kit" from whoever sells them. The carburetor is fairly simple, unlike the 4-barrel American ones. Be sure to hold the carburetor over the parts basket when disassembling. A small ball bearing that functions as a one way valve will fall out of a recess. You don't want to lose that! Ideally, you should have an air compressor so that you can blow the water out of all the ports in the carburetor prior to assembly. If you don't get all the water out, corrosion will be encouraged to form in the wrong places. That may be your problem now!