Stupid question about ignintion and idle adjustment

[halmis]

Hi! Before you can adjust the carb you must set the right ignition timing. The timing should be set to 5tdc at 800 rpm with a strobe light. How could i adjust the timing without adjusting the carb first to idle at 800?

1600 ad engine

[sctbrd]

First static time- adjust the points at the correct TDC point.
Adjust the carb to get it to run good at the proper idle.
Adjust timing with light to get the best timing WHEN AT OPERATING TEMP.
Adjust carbs at idles AT OPERATING TEMP.

[halmis]

[Xevin]

And if you are using points replacement module like Pertronix Dale M uses this technique.

“ Actually you can use static timing (test) light with electronic modules .. Connect one side of test light to #1 terminal of coil... Connect other side of test light to ground ...Put crank pulley at 7.5° BTDC and turn key on, and rotate dist till test lamp lights..... JUST LIKE POINTS..... This will get you "start up" every time you set new engine...

In essence it is what you are doing with your STROBE method....

Been doing it that way for years...... BUT usually set engine at 28-30° BTDC at 3000 RPM for final tune....

Dale
_____________”
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Keep on Busin'

[airschooled]

^ that works 50% of the time.

The other 50% of the time, the test light is already lit when you turn the key on

On the plus side, that’s true for points as well.
Robbie
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[SGKent]

why can't you lower your RPM at idle?
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[halmis]

[SGKent]

each bus model was built with specific equipment, and specific tuning needs specified. Some are hoses on, some are hoses off, some are BTDC, some are ATDC, some are 800 RPM, some are 900 RPM. This all assumes that all parts of the equipment is mounted, connected and functional.

Most Bosch distributors have weights inside that change the timing once the RPM gets to around 1000 RPM. So, if someone has their idle set at 1100 RPM, setting their timing will not be accurate. Hence the RPM should be where VW specifies, and the timing set hoses on or hoses off per the specs.

Many here set it an alternative way. They disconnect all the vacuum hoses at the distributor, rev the engine with a tachometer attached and bring the engine up to around 3500 - 4000 RPM, which is where the timing stops advancing. Then they set it to about 30 degrees BTDC, lock it down, let the RPM fall and hook the hoses back up. The timing will be about correct, maybe a couple degrees off but the engine will run cooler. If you have a vacuum advance, you should make sure that it will hold a vacuum.
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[Wildthings]

This is one of the reason to set your timing at 28-32° before TDC @3800 rpms, with the hoses removed from the vacuum can and plugged. In general this way of timing your engine will still give you the correct time under high load high rpm conditions even if the vacuum canister is bad, or the distributor and/or carb are a bunch of mismatched worn parts. If you set your timing at 5° ATDC at idle both the distributor and the carb must function to factory spec, which is very likely no longer happening.

[halmis]

This table in the manual does not seem to cover my engine. Mine is a 73 1600AD so i have no idea of how to set the timing

[airschooled]

Post pictures of your distributor, pulley, and a close up of the notches on your pulley. Engine code doesn’t matter unless it’s fresh off the assembly line in Germany.

Robbie
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One-on-one tech help for your vintage Volkswagen:

www.airschooled.com

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[halmis]

[Wildthings]

[halmis]

You are going to need to determine TDC by using a wooden pencil or dowel rod into the #1 or #3 cylinder. Alternatively you could just find another pulley.[/quote]

ok, so you dont think anyone here has ever seen these marks before?

[airschooled]

It’s *likely* (but not 100%) that those are the marks for 7.5 and 10 degrees btdc. You can use either one to static time and get the engine started.

With a TDC tool, you can mark exact TDC and use a strobe light with advance to find maximum advance timing. Or you could buy a degree pulley for a little more money. The CB aluminum pulleys are very well balanced and perfectly round, unlike most original steel pulleys that are warped from Neanderthals trying to remove them with screwdrivers.

Robbie
_________________
One-on-one tech help for your vintage Volkswagen:

www.airschooled.com

https://www.patreon.com/airschooled

[wagen19]

[halmis]

[wagen19]

Ok thanks. Whats a ccm engine?[/quote]

ccm means cubic centimeters or 1,6 litres, nothing special.

[halmis]

Why is there a different engine number on the block? Is the number at the pump restamped? Why?

I dont understand these numbers, can someone please explain?

[Wildthings]