351 PCM Prestolite Points Timing

The timing must be way off & the extra wide gap may be compensating. Check the springs on the advance weights - may 1 is broken. Other than that, find a dwell meter to check points adjustment. Also get that timing checked out. Are you sure you are triggering the timing light from #1 cyl (Starbvoard front wire)?

I too had problems with my points this past weekend. Boat ran fine in the morning and got harder and harder to start as the day went on, finally, around 3pm it quit completely, no spark. Checked the points, and they were garbage. Didn't close flat, not even close to concentric, and dirty/burned/cratered. Couldn't even get them running for more than 10 seconds after cleaning them with sandpaper.

Tonight, new set of points, new cap, new rotor, old condenser, gapped at .019 when on the high point of the lobe. I also closed the spark plug gap from about .045 (bad advice from a friend) to .031-ish. Initial timing set with a light at 10* at about 750RPM. Did not check the dwell. It started and idled better than it ever has before. No pumps of the throttle, no giving it a little throttle to keep it running til its warm, just turn the key and its purring.

However, when I bring the RPMs up to 3000-3200 with zero load, timing only advances to about 25*. Guess my mechanical advance isn't working 100% correctly? This should be hitting 32-36* total advance by 3000RPM, right? I'm probably missing out on some top end power because of this as well, no?

Does anyone have a link to a writeup on how to rebuild the mechanical advance unit? Or just a basic explanation? I had the points plate out tonight and looked at the advance mechanism, it seemed to rotate freely, but I'm not really familiar with how things are supposed to work in there.

I got my kit from the local auto parts store, did not see the Petronix name, but it was called an "ignitor", they had Ignitor, Ignitor II and III, but I just got the Ignitor, it was the only one they could get and cost twice as much as the internet Petronix ones. What brands should I be looking for?

A quick rev in neutral (on the hose or at the dock) to verify total advance is appropriate.

TJ - I think OEM was 18* advance at 4000 RPM. I too was hesitant to hold at 4000 in driveway. Just blip the throttle to see that it advancing at a steady rate & call it good.

Best plan is to get a DUI or Mallory distributor. Next step down is a Mallory conversion.