Problems getting my 73 Superbeetle to run

[rusteegold]

Hi all,

I'm new to this site and I have what I hope is a simple question. I hve a 73 Super beetle that starts right up and idles fine but as soon as you start driving (put the engine under load) the engine acts like it's running on 2 cylinders and starts wobbling at about 2000 to 3000 rpm and starts backfiring. It won't even pull the car up a gentle hill. Everything seems to be set up right, but in talking to my neighbor last night, he seems to think there might be an issue with the timing. The firing order is correct, but he seemed to recall that it's possible to get the bug to run even though there might be some setting out of kilter. I have a 1982 Yamaha Virago motorcycle that I rebuilt last year and I actually put the camshaft in 180 degrees off. It ran but not well. I wonder if there is a simple test I should make on my bug to make sure I have all the timing correct.

In the past few months this bug has a new wire harness, new distributer and cap and rotor and plugs and coil and wires and I rebuilt the 2 Kadron carbs last week. Like I said, it idles great but won't pull itself up a small hill.

Thanks in advance,
-steve

[Q-Dog]

How did you time the engine when you replaced the cap, rotor, wires, etc? I don't see points listed. Did you not change them?
_________________
Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[spencerbai13]

If you want to try to static time your beetle, just follow this video. You just need some basic tools and a test light.

https://www.youtube.com/watch?v=787INwvir24

[rusteegold]

Q-dog - yes, I replaced the points also.

spencerbai13 - thanks for the video. I must admit, I did not do the timing... that was done by my son. I'll re-check it tonight and see if I'm off.

Thamks,
-steve

[rusteegold]

I followed the instructions to static time my bug. The timing seemed to be pretty close when I started but I went through the steps just to make sure. However, while I was twisting the distributor, the test light came on but it was very dim (it's a new test light and I tested it across the battery and it was very bright). I also noticed that the coil was warm - not hot, but warm. Is that normal? It's a new Bosch blue coil. and - yes - I had the key turned on and I was connected to the negative side of the coil and I had a good ground for the test light.

[ashman40]

Maybe time to break out a voltmeter (VM) and check the voltage at the battery and the coil #15 (+) terminal. Check the coil voltage both before you start the engine and while cranking the engine. If the voltage drops much below 11v you may have a problem.

You mention checking the timing. Where was it set? Also, what model distributor do you have installed? Have you checked that the distributor is advancing as the engine rpms increase. You will need a strobe timing light for this check.

Lastly, check that your two carbs are squirting fuel from the accelerator pump nozzle when the throttle plate opens.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[rusteegold]

So I watched several videos on youtube about timing my bug and they all seemed to say the correct timing was 7-1\2 degrees before top dead center. One video even made a point to say "some bugs have a timing mark that is about 5-1\2 degrees AFTER top dead center but that not normally how we time our bugs"... So based on all this knowledge I set my timing at 7 degrees before top dead center. But it ran like crap. I was reading my Chilton repair manual about timing and tune ups and it said that my 73 super beetle was supposed to be set at 5 degrees after top dead center, and I noticed that my bug did have a timing mark at 5 degrees after tdc. So I set it there... And now my bug runs fine.

That seems so weird to me.

[ashman40]

This is why I asked about which distributor model you are running? Different models/years came with different distributors. Knowing which model you have installed helps determine how it should be timed.
Look up your distributor model# here and adjust timing as suggested.
http://www.oldvolkshome.com/ignition.htm

Using the wrong timing value just about guarantees bad performance.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[Cusser]

[rusteegold]

Thanks to you who made suggestions to help me. I adjusted the timing to 5 atdc and it worked for about 2 miles then quit suddenly. I let it cool and drove another mile and it quit suddenly. Finally I towed it home, let it cool and started it up and let it idle until it died suddenly. Then i found the problem... My neighbor had installed a tachometer to the negative side of the coil but had run the wire haphazardly under the car. The wire was touching the exhast and when it got too hot would melt and ground the coil. After cooling off it would run for a while.

I disconnected the tach wire and the bug runs pretty good now.

Thanks for all your help.

Steve

[Geoffffreak]