I just purchased the 41 and decided to do a small tuneup on it. When I started I noted that the octane selector on the distributor was set at "0". To start checking the timing I pulled all of the plugs. Then following the #1 spark plug wire back to the distributor, I marked the #1 spark plug on the distributor cap and the distributor body. I then took off the cap. I then manually cranked the engine around until the pointer was directly over the BB and the rotor was pointing at the mark I made on the distributor for the #1 spark plug wire. I assumed that I was now at TDC on #1. I then took the distributor out and checked the point gap and it was set to .016. I replaced the distributor and ensured that the rotor was again pointing at the mark I made. I then attached my static timing light and turned the distributor until the light went on. So I thought I should be good to go but when I looked at the "octane selector" it was not pointing at the "0" but instead it was now pointing to 10 degrees advanced. So given that it was initially pointing to zero, the spark must have been very retarded. Does this make sense? My assumption was that if I had the engine at TDC on #1 that when I adjusted the distributor to get the light to turn on that the octane selector would be pointing to "0". The reason for all of this was that when I purchased the truck it didn't run very well so I decided to look at doing a small tune up.
Thanks for any help
Mike
