Wildman

I have recently acquired what I believe is a 1972 Super Beetle motor and drive train (4-speed).  This is in a Home-made TRIKE.

 

She ran OK when I first got her... I could even get up to 75 MPH with a tail-wind... but she ran rough and looked even worse.

 

After attempting to adjust and tune up, my problems have gotten worse (and it tics me off cuz I am a pretty good wrench)

 

I cannot get her to run right and it is driving me crazy...  first I have discovered a leaky left hand dual-port intake manifold.  Even though that is causing an idle problem, now I cannot get the old girl to get over 60 MPH.

 

I have adjusted valves to .006, set static timing to (0), have one of those vacuum operated distributor, new plugs, old cap & rotor, condenser and wires.

 

Solex 34-PICT with dual vacuum lines to the distributor, electric choke, oil-bath air cleaner.

 

Any help appreciated, I simply need a direction to go....  without having to throw too much money at her..... 

 

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Ryan

For starters, you're timing wrong.  With both hoses connected on a dual vacuum distributer, timing is set to 5 ATDC.  Secondly, what carb are you using?  The dual Vac dizzys (DVDA) were only used with 34PICT3 & 34PICT4 carbs.  If you're using another carb, then disconnect and plug the retard hose and set the timing to 7.5 BTDC.  Actually if you're not required to smog the engine, then I'd disconnect it regardless.

Try that and report back if there's still problems.  --Ryan

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Wayne

Here's some help from Marc Vellat from our Yahoo Beetle Group:

 

Quote:
Dual-diaphragm ("DVDA") distributors are notorious for
developing leaks in the retard side - if yours is one
of those and you set the timing to TDC, it'll be about
7-1/2 degrees retarded from ideal; setting it to the
factory-spec 5 degrees ATDC in this case would make
things even worse, so you'd want to plug the retard
hose to the carb and treat it as an SVDA (timed at
7-1/2 degrees BTDC) as Ryan describes. Easy to check,
simply suck on the hose and see if it holds vacuum -
if the breaker plate drifts back, you've got a leak.
The centrifugal advance part of the distributor is
seldom at fault, but if it's seized performance will
of course suffer; for a quick check, twist the rotor
clockwise and release - it should move smoothly
(roughly 10 degrees rotation) against light spring
tension and snap back smartly when released.
If you've been operating it for long with an induction
leak the lean mixture could've done some harm to that
side - I'd want to run a compression or leakdown test
ASAP.

 

I hope that this help,

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Wildman

Ryan,  thanks for the info..... SO to see if I have this right......  YES it IS one of those dual vacuum distributors..... and NO... here in Montana we have NO SMOG restrictions of any kind.  Are you saying that I should simply disconnect the vacuum lines from BOTH the advance and retard of the Distributor and then try to set the timing to 7.5BTDC?  How do I do that with the stock flywheel that has only ONE little v-notch on the pulley wheel?

 

I know I would be plugging the ports on the Solex 34-PICT carb, but would I also be plugging the ports on the vacuum advance as well?

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Wildman
ALSO guys.... which one of the hoses is WHICH on the DVDA?
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Ryan

The retard line is the one entering the rear of the vac canister, the one facing the fanshroud.  On the carb it's the one that's facing you, not the one on the side.

I would disconnect and plug them both to set the timing.  After the timing is set then you want to reconnect the advance line and leave it connected.  It's the one on the left side of the carb that goes to the front of the vac canister.

As for the pulley markings, that one I can't help you with.  There are so many different types of stock pulleys out there and I've seen more than one that had only one notch, but they weren't the same timing mark.  I would suggest you try a good degreed pulley and use that to set the timing.  --Ryan

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Wildman

OK, Let's see if this old dummy has it now.....  I can disconnect the Retard Hose, plug it at the carb (on the rear, facing me).... and ?? LEAVE ?? the timing set where it is for a timing of "0" at idle and "7.5 BTDC?  If so that sounds easy enough..... and if it works will greatly pick up my spirits from the last couple of days.....  too bad the weekend is over so I could ride her....

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Wildman

OK, just re-read all the posts and I think I've got it..... now.

 

WHICH ONE OF THESE IS RIGHT?

 

1. The timing (which is set statically to "0" +/-) is really TO FAR retarded to give me any real power.....  <AND> ???  WILL the vacuum advance bring it out to 7.5 BTDC   ???   The retard hase has been robbing me of the advance capability of the distributor...

 

<OR>

 

2. Disconnect the REATARD Hose and plugging the Carb side and then re-setting the timing to 7.5 BTDC (+/-) should be done????

 

<OR>

 

3. Am I still in left field, hopelessly confused by the terminology ????

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Ryan

#2 looks right.  Disconnect the retard hose and ignore it from here on out.  Now temporarily disconnect the advance hose and plug it.  Set the timing to 7.5 BTDC.  Reconnect the advance hose and your timing is done.

If the timing has changed, then that means you're drawing vacuum advance at idle (you shouldn't be) and the throttle positioning screw needs to be backed out untill you aren't.  That would also lower your idle speed so you would then need to bring it back up with the larger of the two screws on the side of the carb.  The smaller one is idle mixture.

I should mention that all of this should be done with the engine up to temp and the choke/fast idle disengaged.  The choke controls the fast idle setting so if it's active, it'll throw everything off.  --Ryan

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bumblebee73

i have a 73 super, it had vacume advance . chucked it in the trash and put a .009 mechanicle advance distributer w/34pic3 , plugged off the vacume ports and it runs so much stronger .  

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Wildman

Thanks everyone for all the HELP!!!  Yesterday I have ordered a NEW mechanical 009 distributor, which comes with cap, rotor, points & condenser...  NEW Plug wires (fire engine Red... yeeeehaww), 2 new intake manifold gaskets and a 34-PICT3 rebuild kit.  Maybe I can get some good Fall riding in after I put her all back together.....  Will be posting pics of the old girl soon.  Thanks again!!

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Ryan

The 009 is a mistake, it will only run stronger if your original distributor was toast to being with.  At WOT it doesn't matter, but for just driving around, the vacuum advance will give a better power curve and better MPG.  --Ryan

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Wildman

I am not sure if the Distributor is toast or not.....  it DOES wobble a little when a grab it, the retaining nut is fairly tight and I am hesitant to tighten any further....  is this a result of a worn O-Ring or a worn distributor?

 

I still have the idling issue and will see what happens when I get the intake gaskets and the carb rebuild kit.   I (again) set the timing to 7.5 BTDC statically after getting a measurment from a guy who used his digital caliper to measure the distance from "0" to "7.5" in a straight line on his graduated crank pulley....  it DID make a diference when I fired her up and took her down the road for about 2 miles and back.....  still a lot of flat spots in the throttle but did get up to 68 MPH with some good wind on the road....

 

QUESTION:  After setting the timing, I back it off a little (advanced slightly) to make sure I was NOT too far advanced.....  HOW FAR can one advance the timing before performance suffers?  Is it simply a matter of trial and error?

 

Here is a pic of the old girl.....  sort of out of MADD MAX...

 

 

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Ryan

You can start doing long term damage before you notice a decrease in performance.  Retarded timing causes high EGTs.

Are you sure that your timing mark is in fact TDC?  I'm pretty sure are pullys that had only one mark and it was something else.

Flat spots are usually either timing related or a sign of garbage in the carb plugging up the progression circuit.  Sounds like you're on track to cover both those bases.  --Ryan

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Wildman

By flat spots I mean that upon acceleration she starts to go and then hesitates so I have to give the throttle a good twist and wait..... and wait.... (1-2 secs) before the extra fuel in the system makes its difference....

 

To get any kind of top end the throttle is wide open and I assume wasting mucho fuel...

 

YES, my Crank Pulley only has(had) one notch in her and I simply used the measurements provided by another enthusiast (0.4175") and made a scribe mark clockwise from the TDC notch.... and then set the timing to that.

 

I will post a pic of the mark I made tomorrow night after I get back from the show.

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