1995 Mercury 175 2.5l carb stator question

**Rider_560** · 09-19-2018, 07:23 AM

I did dva yesterday evening with a fluke multimeter. First tests at 1k rpm. All measurements were in spec except stator dva test blue to ground. The volts on 2 coils were low, at first. Same 2 I was having firing issues with before. The volts on cylinder 1 and 5 (started as 2 and 6 then moved switchbox and firing problem moved with it) were low, around 1.5v, coil 3 was in the 200s (spec 125-175). The dva reading on the blue wire to ground was 295 (spec 195v-265v). Then I revved the engine a couple times (before spark was weak on 1 and 5, revved the engine, back to neutral. Spark then jumped 7/16" gap). Then re-did the dva readings on the coils 145v on all 6. Re-did dva reading on blue to ground, it was 210 (spec 195v-265v). I then checked all circuits at 3000rpm. All were within spec. I then rechecked values at 1000 rpm. All within spec.

I believe the short circuit in the bad switchbox is causing high voltage in the stator and low voltage to the coil. When revved and the short clears, voltage returns to normal at coils and stator. Would this be a plausible assumption? Is my stator likely bad? I have 2 switchboxes arriving tomorrow and don't want to ruin them. I don't mind buying a stator, I just don't think it's bad. I'm going to redo all DVA tests tommorow after the new switchboxes are installed. Would the testing procedure be enough time to ruin the boxes?

Thanks for any help in advance.

**Rider_560** · 09-19-2018, 05:29 PM

Need some help please!! First time using DVA. DVA is attached to fluke multimeter.

I redid readings today immediately after installing new CDI electronics switchboxes. Revved motor to 1k rpm. I'm going off of my tach, not sure how accurate it is. Volts on red and red/white stator leads were low, 95-100v on red and 110v on red/white. Spec is 120v-160v. Blues were in spec. I cut the boat off. Literally for Less than 1 minute. To walk to the truck (attached to the boat) to grab a pen and write down readings. I cranked the boat back up. Never revved it or anything. Slowly revved back to 1k rpm. Specs were then 135v on red, 130v on red/white (spec 120v-160v). Blue checked 205v, blue/white 195v (spec 195v-265v).

I then revved to 3k rpm, to check those specs. 268v on blue, 275v on blue/white (spec 255v-345v). 270v on red, 268v on red/white (spec 230v-320v). I was going to cool and recheck but ran out of gas.

My stator may be bad but I'm not 100% convinced. I had 138v-145v at all 6 coils the whole time. Spec is 125v-175v. What do you guys think, is my stator good to run?

**Rider_560** · 09-19-2018, 05:30 PM

Again, I'm not sure how accurate rpm tach on dash is. All were in spec on second start up. Motor was no warmer or cooler for second startup.

**Rider_560** · 09-20-2018, 06:54 AM

Anyone?

Is the CDI trouble shooting guide based on cranking speed? There spec is 25v-100v red and 180v-400v blue

**Rider_560** · 09-20-2018, 11:17 AM

Talked with a CDI electronics tech support guy this morning. He claims my numbers are within spec, even the initial low reading, per their books. I will retest this evening and let everyone know if anything changes.