1985 85hp ignition diagnosis

[MostlyHrmlss]

Here's what I've come up with, just wanted to submit it for a sanity check:

Wired normally, I get no spark on #3.

Swap coils w/#2, still no fire on 3, still have fire on 2, so all three coils are good, right?

Swap trigger inputs, and I only get fire on #2, so all three triggers are good, right?

Stator reads 700 Ohms on one side, 2400 on the other, so I need a new stator, right?

Swap stator inputs, no fire anywhere, so CD box for #3 is bad, right?

What do y'all think?

 

[jason32038]

Re: 1985 85hp ignition diagnosis

Swap one of the other hots from the stator to the cd unit for 3. Crank the engine. If you get spark on 3 the stator is most likely the problem. Well obviously you need a new stator anyway judging by your tests so start with that and see it that fixes the problem first.

 

[MostlyHrmlss]

Re: 1985 85hp ignition diagnosis

I thought I had covered that with swapping the stator input plugs, but I wasn't sure about it since the normal plug for the #3 CD only has one stator input wire and the other one has two. Is this what you meant by "Swap one of the other hots from the stator"?

 

[jason32038]

Re: 1985 85hp ignition diagnosis

Yea you might have to splice them.

 

[Frank Acampora]

Re: 1985 85hp ignition diagnosis

Depends upon your definition of what one side is. On three and four cylinder engines, the stator has three windings. Two high resistance windings generate about 150 volts to charge the CD boxes, while a relatively low resistance winding generates 12-16 volts to charge the battery.

On three cylinder engines, the two blue wires are joined and charge one side of the first CD box (#2 cylinder) while the two yellow wires charge #1 in the first box and #3 in the second respectively.

You check resistance by (with the wires removed from their terminals) probing with a VOM. Pos. probe to yellow and neg. probe to blue. USUALLY, resistance will either be infinite for a broken but insulated winding or when neg probe is grounded, zero for a broken and grounded winding.

If you are not getting spark on #3 and suspect the CD box, switch the yellow wire and coil from the first side of the box to the other side--The second side is unused and usually will be good even if the first half has failed.