I set valve clearances at the 10° timing mark. Bug is not happy.

[the_8th_dwarf]

[jarmchairpilot]

Do you run points, if so that's the first thing to check is the condition and set the gap correctly.
If electric ignition then you check the ignition timing with a strobe light After you have adjusted the valve gaps according to spec. nearly always 0.15mm..for most bugs.
A service including oil change is always a good idea
I replace distributor cap,rotor,spark plugs and ignition leads every 5 years because my bug is my daily driver.Buy the best Bosch quality where possible,German,Mexican,Brazilian in order of quality.
Change fuel filter every year too,it's crucial to keep carb clean.

[joemama]

Did you by chance disconnect the plug wires? If so, check the firing order.

[ashman40]

Short answer, it does not make a difference in the adjustment if you are a few degrees off from TDC when you set the valve gap. +/- 10deg makes no difference.

Ignition timing and valve timing are two different things. The crank pulley timing marks are primarily for ignition timing.
The TDC mark is used when setting the valve gap, but only as a means of making sure the specific cylinder you are adjusting is near TDC at the end of the compression stroke. You want to be near the TDC mark for cylinders 1 & 3. You want to be near the BDC mark (or about 180 crank deg off from TDC) for cylinders 2 & 4. Each cylinder must have both valves closed when making adjustments. The range of cam degrees when both are closed is rather large and the corresponding crank degrees is twice as large. You do not need the crank to be exactly at TDC when making the adjustments. You can actually be quite a bit off from TDC and still be fine.

61SNRF’s pics illustrate this...

[the_8th_dwarf]

[ashman40]

[bnam]

[airschooled]

Back in ye olden daze, the Germans set the valve lash to .004" because that is exactly what was required for the engine. In the late sixties, VW couldn't figure out why American engines (their largest market) were burning #3 exhaust valves at an alarming rate, so they sent inspectors across the pond to investigate.

As it turns out, when American mechanics finished their daily shifts, they put their tools down and hit the bars. The next morning, they pulled that day's cars in for tune-ups, and adjusted valves on "cold" (not really) engines. Those .004" valve lash specs on "cold" engines shrank down to .002" when the engines were actually allowed to sit overnight, (heat expansion is a bitch.) Meanwhile, the Germans, (a more fastidious group of mechanics,) put their tools down at 4:50pm, and pulled the next day's cars into the shop. By adjusting those valves truly cold, their cars didn't have the problem of dropped valves.

VW gave the American dealerships two choices: prep your work before visiting the pubs, or set the valves to .006" the following morning.

The sticker on our fan shrouds tells us which path the American mechanics chose.

Robbie
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[modok]

[bnam]

@modok,
Even if the they are all at different temperatures, as long as the warmest is less than 50C, it would seem to me that setting gap would be ok as the most variance between the different valves which are presumably at different temperatures (but all below 50C) - would be much less than 0.0002" (which is how much the gap would vary if set at 50C and later measured at ambient - IFF my calc is roughly correct).

Again - just trying to rationalize why the factory manual says it's ok to do timing as long as temp is below 50C. Not recommending it. And I prefer to do it cold.
_________________
1971 1302LS Convertible (RHD) owned since '74
Click to view image
1965 Karmann Ghia Coupe - under restoration
1966 Fiat 1500 Cabrio (with 1600 Twin cam)
1952 Citroen TA 11BL

[modok]

I'm not sure if you are calculating that right.
Roughly the difference in expansion between iron and aluminium is .001" per 1 per 100degrees f

four inches of cylinder, 50f, that's a difference of .002"

Then again the valves are ALSO about 4", so that would cancel out the cylinder, if we assume the heads and cylinders and pushrods are all at the same temp, which is plausible.

But the CASE, would probably be last to cool, and magnesium has 2.5 times more expansion than iron. if the case was 50F hotter than the rest it would have you adjusting your valves ABOUT .002" too tight.