Bought a SB '73, having some problems

Roger: Congratulations on your nice "new" car. I gather that you are in Holland?

Hard to start when hot is a very common problem, especially when the weather is warm outside.

The problem can usually be traced to flooding of the engine by excess fuel dripping from the carburetor. (There might be other reasons, but I would begin here.)

After the engine has been shut down while hot, the heat is absorbed by the carburetor and the fuel inside. The fuel can get so hot that it begins to boil! Yes! The boiling fuel then percolates out through the brass vent tube and into the manifold.

If you remove the air cleaner immediately after stopping the engine when hot, you may see a "cloud" of white smoke or fog inside the carburetor. This is the vapor of hot fuel.

A second possible cause is excessive fuel pressure in the fuel hose feeding into the carburetor. If the pressure becomes too great, the needle valve can be forced open and fuel pours into the bowl, overfilling it. The pressure increases due to the high temperature .

Also, the needle valve might be defective or has not been tightened properly, allowing leakage.

Speedy Jim

Also Check the choke is ajusted correctly.

Trying to start a hot engine with the choke closed is tough !

Rich

Yes indeed, Holland, the country that will get it's as kicked in Germany the next few days... :)

So it is most likely a fuel problem? I'm once told to floor it when crancking, but what I read in your explanation the carb is getting too much fuel already? Does this mean not to use the trottle? The fun thing is it runs like stink once fired up, pretty fast for a

1300cc...

Today, I've checked the valves, dwell and ignition. (what a shocking experience:)) Played a little with the choke (will set it back a little cw between the first and second notch) I understand the carb is harder to adjust than a 30pict1? Last week i found a link on the internet for this carb but lost it somehow, any pointers? How do i set back the fuel flow if it is too high?

Sooo many questions.... and probably more to come 8-) Thanks, Roger

Yes, use the throttle when cranking. Just hold it wide open (pedal to the floor). That will help the engine to clear out the fuel in the cylinders.

There is no adjustment for the fuel flow as it relates to this flooding problem.

Rob and Dave have some excellent articles on the carb (and more):

Jim

"> Yes, use the throttle when cranking. Just hold it wide open

Hey Jim,

Well, it is going from bad to worse :( As i mentioned before i played a little with the choke ánd timing... bad bad bad... Now the engine misses sometimes when accelerating (say 90km in 3th). This must be something related to the ignition, right? How is the timing adjustable when having a stock pulley (no degrees on it)? If i turn the dizzy a little to the right... (i think....clockwise??) the rpm increase a little and the notch moves to the left using a light. Is it possible to adjust timing by listening to the engine? (all the way to the left is max rpm at idle) Before i loosened the dizzy i marked the position on it so that it is easy to readjust everything. I guess it is now one mm of, is that enough to mis sometimes at higher rpm? Could a tight or loose valve stem be a culprit?

So much to learn,

TIA Roger

It can be dangerous to time it "by ear". Too much advance will cause damage to the piston tops.

Euro cars used different distributors than we have so the timing specs for your car may be different. If you can find the part number on the side of the dizzy, go here and try to find the spec:

The valves are not a common problem related to misfire. I would think more of ignition-related causes.

---------- Off Topic: Do your countrymen of today know of the history of Ben Pon and his importance to the VW story?

I was a boy in New York at the time the first VW's arrived on ship. Ah......but that is another story.

Jim

This morning I re-adjust the valves. They were a loose .006 and since some guy's use a .004 gap i thought i make it a tight .006 (1.5mm) fit. Gapped the points to a tight .04 mm (like it was before) And turned the dizzy a bit to the other side of my marked pensil line. Hopefully it wont be harmfull (aprox 2mm turn) No more misses at higher RPM (or at all for that matter)

I think here the airheads are the only one known to that fact, however we do have a volkswagen museum in holland which is called the Pon museum

Sorry, my previous mail was sent before i ended it...

....I've never been in the Pon museum.. I can't even find it on the internet but I'm told there is one in Amersfoort...

Anyway, Jim thank you for your wise lessons on this topic, I hope there will be many more to come... :)

Roger

I think adjusting the valves to making it a tight .006 gap is a mistake. I would have adjusted them to a loose .006 gap. The valves should only be adjusted with the engine cold from sitting over night.

Your fuel pump pressure might need adjusting.

You might be able to adjust the timing with the 'static timing' method.

You can find most of your answers at Rob and Dave's aircooled vw help pages here at

But what about adjusting to a .004 gap? I know people use that adjustment, with alu rods if i'm not mistaken

How do i adjust my fuelpump, it's that cheap brazilian one not the electric.

Yeah they are a great resource!! However i did adjust the valves in a different way than them; Three left one right, turn the pulley 180dgr and then one left three right. Did it also on my '59 and it still runs fine.

Thanks, Roger

Forgot to mention: A loose .006 was in this case tight .008. My guess, too loose... (probably yours too:))

Thanks Roger