Hey wrench check these numbers out

[176champion]

1995 merc 200 xri falling on face...checked stator and switch boxes you see anything wrong?

Retested stator and switch boxes and here are the results

Outer box first stator to box

red wire idle 56  3,000 rpm 240

black yellow  210 idle  280 3,000

blue wire 210 idle 250 3,000

white black 10.5 idle 29 3,000


Inner switch box

red 75 idle   280 2 3,000

black yellow  210 idle  280 3,000

blue  210 idle   280 3,000 

white black  8.30 idle 24 3,000


Switch box it's self to coils

outer box first

green idle 150  90@ 3,000 rpm

green white 170 idle 175 3,000

white this one has w white wire on bottom..180 idle 160 3,000

Inner switch box

green red 186 idle 225 3,000

gr/white 180 idle 225 3,000

green 185 idle 235 3,000

so there are my readings at this time....would like opinions.

[fishinwrench]

7 hours ago, 176champion said:

1995 merc 200 xri falling on face...checked stator and switch boxes you see anything wrong?

Retested stator and switch boxes and here are the results

Outer box first stator to box

red wire idle 56  3,000 rpm 240

black yellow  210 idle  280 3,000

blue wire 210 idle 250 3,000

white black 10.5 idle 29 3,000


Inner switch box

red 75 idle   280 2 3,000

black yellow  210 idle  280 3,000

blue  210 idle   280 3,000 

white black  8.30 idle 24 3,000


Switch box it's self to coils

outer box first

green idle 150  90@ 3,000 rpm

green white 170 idle 175 3,000

white this one has w white wire on bottom..180 idle 160 3,000

Inner switch box

green red 186 idle 225 3,000

gr/white 180 idle 225 3,000

green 185 idle 235 3,000

so there are my readings at this time....would like opinions.

The one I "bolded" is out of spec.   If there is an additional green wire from the advance module on that terminal then disconnect it.   

You need 140v minimum on that green primary wire.  

If it has the "High Speed Advance Module" mounted on top of the port cylinder head then get rid of that thing and don't look back.  You'll have to study the difference between it and an "idle stabilizer".   You can leave the idle stabilizer, but definitely terminate any HS advance module (they look alot alike, but are identified either by part# or wire colors).

[176champion]

Yup i agree, the outer switch box is bad which control 2 4 6 cyl which is the side i had troubles with..i have also removed idle stabilizer and detonation box ...2 new switch boxes ordered...Thank you..

this is on my new ride took it out Sunday and it fell flat on its face, then it would run for about 2 minutes then back down to 2000 rpm or something like that...1995 Merc 200 xri fuel injected.

[fishinwrench]

Test the voltage regulator before you haul off and buy new switchboxes.   That one primary falling off at higher RPM's is kinda odd.   Not a typical switchbox failure by any means.

Might not hurt to swap coils around too, just to be sure that one isn't arching to ground.....which would also show up as a dropped primary on the meter.

[176champion]

Motor has new CDI regulators, all 6 new coils and plug wires and a new i think CDI stator..previous owner said they had been chasing a dogging out of the hole problem, well it not only bogs out of the hole but once it does take off it just bogs right back out, had up to 63 mph and it just dump on me...lol..still had old original switch boxes..i had already ordered new ones figured it wounldn't hurt. Oh and the tach dropped out just before it shut down, may be just coincident.

[176champion]

3 hours ago, fishinwrench said:

The one I "bolded" is out of spec.   If there is an additional green wire from the advance module on that terminal then disconnect it.   

You need 140v minimum on that green primary wire.  

If it has the "High Speed Advance Module" mounted on top of the port cylinder head then get rid of that thing and don't look back.  You'll have to study the difference between it and an "idle stabilizer".   You can leave the idle stabilizer, but definitely terminate any HS advance module (they look alot alike, but are identified either by part# or wire colors).

Stabilizer and advance module is gone..i took them off the other day.

[fishinwrench]

4 hours ago, 176champion said:

Motor has new CDI regulators, all 6 new coils and plug wires and a new i think CDI stator..previous owner said they had been chasing a dogging out of the hole problem, well it not only bogs out of the hole but once it does take off it just bogs right back out, had up to 63 mph and it just dump on me...lol..still had old original switch boxes..i had already ordered new ones figured it wounldn't hurt. Oh and the tach dropped out just before it shut down, may be just coincident.

This is gonna be a fun one 😃

I've never seen a switchbox that produces sufficient voltage at cranking speed...but won't at 3k+.   I almost wanna say it's impossible for anything in the switchbox to cause that.   I'm still leaning towards a VR problem, or possibly a bad shift interrupt switch (if so equipped). The shift switch is designed to momentarily kill the spark to one bank, which helps the motor shift more smoothly.

Put a timing light on each plug wire, run it up, and verify for 100% certain which cylinder(s) are loosing spark. 

[176champion]

I don't see a shift interrupt switch on it, i'll unhook regulators and  recheck it to see if it changes the voltage on that one lug also. thanks

[JestersHK]

My engineering brain has really enjoyed this thread( sorry for the misfortune though Champ  ).  Hope you guys can get this figured out!  Wrench hopefully your " This is gonna be a fun one" quote is not the same as mine. Last one involved 4 hours under a truck to find and finally replace a $28 crankshaft position sensor... I did find out why the dealerships all wanted $400 to replace though...

[176champion]

Wrench do you have a brass magnet?...lol...switch boxes changed..inner to outer and outer to inner.. time to pull it out of garage to around back and get wet...lol