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Fri Oct 24, 2025 3:32 pm

Hello all. I’m trying to time my 1962 bug, it’s has a 28pict carb and a ZV/PAU 4R1 vacuum advance distributor. The pulley only has two notches on it that are pretty close together. Not sure what degree those notches indicate and how to properly time it with this set up.

Fri Oct 24, 2025 3:53 pm

The marks are probably 7.5 BTDC and 10 BTDC. 1962 would be static timed to 10 BTDC if that distributor is the stock one (sorry I'm not sure what part no. a 62 should have). That said, it's always a good idea to verify the actual TDC on the engine before trusting the marks because there's a lot of different pulleys out there with a variety of timing marks.

Fri Oct 24, 2025 8:20 pm

Yeah it’s the original distributor, what is the proper way to check for TDC?

Fri Oct 24, 2025 11:19 pm

If the pulley is stock then the most advanced mark is 10° BTDC. That is the correct timing for a 40 horse Bug engine. The most advanced mark is the first one that points strait up, lined up with the case split, and the engine rotates clockwise.

TDC is about 15-16mm to the left of the 10° mark. It is not normally important to get exactly right. There may be a smooth dimple on the outside half of the pulley at TDC (not sure what year VW started that).

Sat Oct 25, 2025 1:00 am

From august to october 1960, the stock pulley has only one mark on 10°, no dimple.
From november 1960, the stock pulley has two marks, no dimple. The left one is for 7,5°, the right one for 10°. The right one is correct for the ZV/PAU 4.

Sun Oct 26, 2025 9:17 am

I fount TDC by pulling spark plug #1 and rotating clockwise till the straw I used was at the highest point then marked the pulley. I’ll time the bug to 10 degrees BTDC, thanks!

Tue Oct 28, 2025 3:23 pm

My bentley book says static time to 10 degrees. If the engine pings, then use 7.5 degrees. It also states to static time only.

Tue Oct 28, 2025 3:37 pm

Chad.S wrote: I fount TDC by pulling spark plug #1 and rotating clockwise till the straw I used was at the highest point then marked the pulley. I’ll time the bug to 10 degrees BTDC, thanks!

Uhm... you understand that this happens twice in a complete cycle, right? Top of compression AND top of exhaust stroke. :idea: You also need to look at the rotor OR the rockers on cylinder number 1

Tue Oct 28, 2025 9:47 pm

The ZV PAU 4 R 1 is a pretty rare distributor. It was installed only on Ghia and only for 6 months in 1960. Not to worry though, it has the same timing specs as the ZV/PAU 4 R 5 and other big cap distributors. The main difference is in how the internal condenser lead wire is routed and minor differences in the original points geometry.