Step one: Head down to Harbor Freight or Walmart and buy a timing light for $20...
You can try by vacuum- try to bring it to 20 Hg at idle, but a timing light is much more accurate
How do you set the timing for an 1989 Chevrolet G20 van - 350 cu. in. with tbi?
you don't the computer sets it from the crank sensor
If the engine is stock, I'd set the initial timing at 12, make sure the timing mark starts to move when you rev the engine off idle, and watch it advance up to somewhere in the 30 - 35 degree range when it stops. Do this with the vacuum advance disconnected. Then with the timing set at 12 with the engine at idle, hook up the vacuum line to the distributor and see that the timing now shows somewhere in the high 20's to low 30's of timing.
Doesn't this engine use a rim fire plug? No gap to set on those.
20 degrees Celsius is about room temperature. At room temperature, mercury is a liquid.
read owners manual The owner's manual says to use the sticker on engine's bay, the sticker on my astro 1986 is missing, and I know timing can be adjust because is lacking power and few others............there must be a place where we can get the right timing 12 degrees 20 degrees..................
The firing order is 1-8-4-3-6-5-7-2 Initial timing should be set at eight degrees and should come up to 20 degrees at a couple thousand RPM
A 1993 model, 20 hp Mercury outboard, has a dry weight of 112 lbs.
Since Mercury has a melting point of −38.83 °C, at anything above this temperature, it becomes a liquid or a gas. For example, at room temperature Mercury exists as a liquid (Room temperature is around 20°C (68°F) to 25 °C (77°F)). Therefore, mercury is not a solid at 36.9 degrees celsius.
Step #1. Bridge #4 and #16 pins on the OBD input to negate automatic/respective advance using a 20 guage length of wire. Shoot with a variable timing light to 8-11 degrees depending on altitude.