800RPM idle, good accel, timing off by 20 degrees!

[madkaw]

You need to look and mark your timing marks on the pulley carefully. I almost bet you are sitting at 20 BTDC at idle and not 25. More than likely you have 17 degrees of mechanical advance with that dizzy and that would total you out at 37 WOT.

20 degrees idle advance would start and idle easier without choke because all that advance makes for a strong idle. Does your vacuum advance work? That’s where you might run into issues . You might be adding too much advance at cruise and be causing detonation that you can’t hear . Might suggest getting an Advance type timing light to check full mechanical advance and vacuum advance. 

 

Check your vacuum advance is working properly and not sticking 

I’ve run all my motors with close to 20 degrees at idle ,  with no vacuum advance. I also had cams that ran better that way. Figure out what dizzy you have with the chart below. 

Just 45 miles south of you I noticed!

Edited September 9, 2019 by madkaw

[DannDZ]

50 minutes ago, madkaw said:

Just 45 miles south of you I noticed!

Very close, I live in the Center Grove area.

Thanks for your advice and the table. It will certainly be helpful when I try to figure out what is going on. I may not be as far off as I suspect. What I really don't understand is why this is so far from the "factory specs" in all the manuals.

Regards,
Dann

[Zed Head]

3 hours ago, DannDZ said:

What I really don't understand is why this is so far from the "factory specs" in all the manuals.

Could be that your damper pulley has slipped and the marks aren't correct, or that the vacuum hose has somehow been attached to the wrong vacuum port.  Distributors use "ported" vacuum, that is only active when the throttle blade is off-idle.