My timing has always been set at 10 degrees btc initial. When I checked it today, it was around 20-25 degrees. It is running seemingly fine with no detonation. Could the balancer have slipped?

I'm not an engine expert, so any advice will be great.

 

I would get a TDC stop and check your balancer.

 

If the damper has slipped, it's not damping any mo'. Bad stuff can happen.

 

If it isn't running any different, yeah, the damper slipped

 

I moved mine back and forth chasing something similar once upon a time and finally decided the advance was sticking and making the idle go all over the place.

 

Good point, could be defective advance mechanism inside distributor.

 

The advance mech is located under the points plate and they stick quite often. The factory service manual said to lubricate it when doing a tune up. which was about every 6000 miles back in the day. There used to be a wick in the center of the shaft that you would put a couple of drops of oil on that would lubricate the mechanism. Check to see if you have one it will look like cloth or cotton in the center of the shaft. I would take a picture but i have had a mallory distributor since 1978.

 

Just to be sure,.... when you checked the timing and found the 20-25* you did have the vac advance line off and plugged right????

 

I sure did.....

 

Run it up and down the RPM band with a timing light on the damper. It should advance to maximum advance around 36° BTDC smoothly and return to base idle timing without sticking or "scatter".

 

That was next on my list. If I do get the correct 36, and it is still at 25 at idle, then it sounds like the dist has a problem or the balancer slipped from what everyone is saying....

 

Matt - a few details about your set up will get you more informed answers.