What should the timing be set for, basically 525sc motor with Mallory distributor with pertronix conversion with MSD 6A box. What rmp do i set base timing and what rpm for total advance?? THANKS

As per the Merc manual, the 525 SC is 35 deg BTDC at 4500 rpm.
So simply subtract your advance from there to get base setting.

PS: timing at idle is (19deg BTDC w/ firepower)
(13deg BTDC w/ t-bolt)




Darrell.

Looking at a spark advance table in the Manual it also shows this:

T-bolt IV:
Initial: 13 deg
Module adv: 22 deg
Total adv: 35 deg

Firepower:
Initial: 18 deg
Module adv: 16 deg
Total adv: 34 deg



Hope this helps out.


Darrell.

Stock 525SC's only have 7.5 to 1 pistons and can run more timing because of lower CR. Based on 35* total, I would retard timing 1* for every .25 point of compression more than 7.5 that you have. That is asssuming you are running about the same 5.5# of boost as a stock 525SC.

according to weiand you want no more than 26 deg total, need to set the dist with little to no advance, with low compression starting not a issue, a locked dist will help clean the idle up if running a decent cam...Rob

I run 30* total with 177s and 9.5:1 static compression. It seems to be the sweet spot.