tearing my hair out- new packs, trigger,stator - STILL intermittent miss. 85 blackmax

**Fstarockr** · 11-09-2019, 12:23 PM

Reposting this in the technical section: (original post here: https://www.screamandfly.com/showthr...98#post3172098)

its a 200- near idle its mostly on #1 and on and off on the opposite bank, around 1200 about 3-4 cylinders get an intermittent spark. im going nuts here- all dva and ohm readings checked out except for the bias circuits, one pack was 7000 ohms out so i replaced both.

Ive removed the kill wires, tach, reg/rect - nothing. cables and grounds good, i loosened and snugged them all on the coils.. I initially swapped #1 coil with #2 thats fine and the miss moved indicating something higher up (packs/trigger/etc)-

either way im stumped.

can someone help? ideas? I have the dva reader and cdi book- im starting to wonder of there is an issue in the actual flywheel, all magnets look good - no cracks, nice and clean too-

thanks. im on the verge of heading over to justanswer!

fyi replacement parts were from cdi (packs) and sierra (stator and trigger) -

New plug wires, coil ohms are fine. All passed a open gap 9/16 with strong blue arc - but intermittent miss visible there too-

**Merc 2.5** · 11-09-2019, 05:00 PM

What did u do when u swapped coils for 1 and 2? U said it moved with the coil? Coils have magnets also that can crack /break and give this issue

**ironhead stv** · 11-09-2019, 08:23 PM

Key Switch

**Merc 2.5** · 11-09-2019, 08:47 PM

Originally Posted by ironhead stv

Key Switch

Doubt that gives intermittent spark. Either all or none power wise. Just went thru that on another thread

**Motv18** · 11-09-2019, 09:38 PM

Agree with merc if problem follows the coil it’s the coil.

Iirc shift switch also cuts half on cdi.

**PanRonnie** · 11-10-2019, 02:27 AM

Maybe another fly wheel!? ��

**Fstarockr** · 11-10-2019, 11:34 AM

yes im starting to wonder if flywheel has issues-

when I swapped coils (i mistyped probably)but i swapped the trigger wires and issue moved, indicating it was NOT the coil.

is 200v on red wires at idle bad?

**PanRonnie** · 11-10-2019, 12:54 PM

would this help!

**eli** · 11-10-2019, 01:25 PM

Motor is 38 years old ,as i said before do a or have someone do a proper leak down then if it checks out ,do a carbon cleaning carbon can create lots of woes

**Mark Poole ModVP** · 11-10-2019, 02:39 PM

Ask Capt.Insane-o

**Dave S** · 11-10-2019, 07:45 PM

I have seen bad coil grnd wires cause bad fire.... next try FLW.....some times it takes a good cussin......

**Capt.Insane-o** · 11-11-2019, 03:59 AM

Originally Posted by Mark Poole ModVP

Ask Capt.Insane-o

Shops closed for the winter.

**Motv18** · 11-12-2019, 11:26 AM

Does it clear up over 1200?

you might have a circuit overlap issue in the carb, going rich or lean as you open it up.

**Fstarockr** · 11-12-2019, 01:38 PM

im talking ELECTRICAL miss on the inductive tach light. its NOT carb related, the strobe keeps popping, no it almost seems to get more pronounced around 1200.. ill put the boat on the trailer and see what the power does-