200 2.4 major power loss.....switch box?

[B.Mac]

Went out today, ran great @ 80 mph for two-three passes. Then while investigating questionalble waters I ran aground, not bad, just enough to swamp the motor a little. Ok trimmed up & idled over to deeper water. Went to take off, no power....... won't even get up on plane. Usually if I sit still and let the motor run out of gear & blow it out a little it usually comes back to life...... No luck this time. Idles ok, spins up but sounds a few holes short , will not pull. Feels like I dumped two maybe three cylinders. I idled all the way back 3 miles to the launch with the cowling off so I could feel the block & heads for overheating while my buddy steered. Seemed to run at right temp. as I was worried I may have dropped a carb. Well my question is does each switch box control three plugs? It seems to be running just well enough not to stall @ idle but has no power at all. I'll check for spark tommarro. I'll check all my ground wires & primary ignition wires. Don't have a spark board so I'll pull my wires off while it runs & see if I lose RPM? I'll probably get knocked on my can tryin to pull the wires. Any suggestions? Sound like a switch box to you guys? Any input much appreciated. B.MAC

[patchesII]

each box controls a bank of cylinders. easy to check, pull a plug put the wire back on it , make sure its grounded to the block and have a buddy crank on the motor to check for spark. my motor did the same thing , would barely get out of the hole and wouldn't go faster than about 30. switch box it was.

[laser]

My 2.4 200 did a similar thing this spring. I had it out on the water and it would idle great. When I hit the power it would start to come up on plane but didn't quite have enough power. I tested a bunch of stuff and found that at 3500 rpm I would loose one bank of cyl's. I posted my question to the board a received a bunch of good advice, I'll see if I can find the thread. In the end I didn't really narrow it down to a single piece.

First I tried a single switch box, borrowed one. No difference. (Yes I did check to see if I replaced the right one). Then I thought it might be the high speed windings in the stator. Couldn't borrow one so I bought a new one, didn't help. Finally I bit the bullet, summer was rapidly slipping away. So I replaced the flywheel, got a used one and this was very likely the problem. But I also replaced both switch boxes and all the coils. As I said summer was burnin' and I was tired of messing around. But with all that stuff replaced it ran great, better than it ever had before.

If you have access to another 2.4 200 you might try swapping some parts such as the flywheel. Likely save you some bucks. Sadly for me, they are kinda scarce around here.

[laser]

http://forums.screamandfly.com/showthread.php?s=&threadid=2288

Some very useful testing stuff on there.

I also replaced the trigger, got that and the switch boxes form Liqui-Fly.

Good luck.

Here I copied the testing stuff from the thread. And the person that deserves the credit.

MadMat
Senior Member

Registered: May 2001
Location: Remote
Posts: 209
I had exactly the same symptoms as you on an 85 XR2. Motoring along, sudden failure, then couldn't even get boat on plane. In my case the stator was shot. I don't have a DVA meter, but found a way to test it without and got useful results, hopefully this will help you too.

Get a conventional multimeter that can read AC up to about 200 volts. Then start the engine up and take several readings between the red, red & white, blue, blue & white wires and earth. (Between each colour and earth).
Blue & Blue & white should match.
Red & Red & White should match.

I took readings at various rpms (idle, 2000, 3000, 4500 I think). If it is a stator problem, at some point you will see there will be a mismatch between the colour wire to earth and the colour with white to earth. (I plotted a graph and got 3 straight lines that increased and 1 increased a bit and then pooped out. I was really surpres by how straight the lines were as this is hardly lab conditions.)

You do need to get a DVA meter to read the output from the switchboxes (into the coils) because the duty cycle is so short you can't get a reading from the switchbox outputs. However the duty cycle from the stator is enough that you can get good readings following my details as above. (Your AC multimeter is reading RMS volts rather than peak so is a bit lower than the peak reading.)

Rapair have some good stuf about troubleshooting the ignition system with minimal tools: http://www.rapair.com/cdi/cdi.pdf

I've cut & pasted the relevant bit for you at the end. Hope this is some use to you.
Cheers
Matt



MERCURY TROUBLESHOOTING
TROUBLESHOOTING ALTERNATOR DRIVEN IGNITION
(NOTICE: Maintenance-free batteries are not recommended for use with these systems!)
Recommended Tools:
For DVA: Fluke Multimeter with CDI #511-9773 Peak Adapter, (or CD-77) and CDI #511-9770 Piercing Probes
CDI #511-9710 Trigger Tester
CDI #511-9766 Spark Gap Tester
Jumper Wire
Note: If CD-77 is used for DVA, you will need a good volt/ohm meter
1) Disconnect the kill wire(s): Connect a DC volt meter between the kill wires and engine ground. Turn the ignition
switch on and off several times. If, at any time, you see DC voltage on the kill wires, there is a problem with the
harness or ignition switch. Battery voltage on the kill circuit will destroy most CD units.

2) Visually inspect stator for cracks or varnish leakage: If found, replace the stator. Burned marks or discolored
areas on the battery charge windings indicate a possible problem with the rectifier.

3) Unit will not fire: Disconnect kill wire AT THE PACK. Check for broken or bare wires on the unit, stator and trigger.
Check the DVA voltage of the stator, (on 3 and 6 cylinder models read from each red and blue wire to engine
ground; on 4 cylinder read between the two red wires and between the two blue wires), with everything connected.
The readings should be approximately 180 volts or more on the blue wires, and 30 volts or more on the red wires.
Disconnect the rectifier. If the engine fires, replace the rectifier.

4) Engine will not kill: Check kill circuit in the pack by using a jumper wire connected to the black/yellow terminal or
wire coming out of the pack and shorting it to ground. If this kills the engine, the kill circuit in the harness or on the
boat is bad, possibly the ignition switch.

5) High speed miss: Disconnect the rectifier and retest. If miss is gone, rectifier is usually at fault. If the miss still
exists, check DVA voltage (between the red wires on 4 cylinder, or red wires to engine ground on 3 & 6 cylinder) of
the stator at high speed. NOTICE: use caution when doing this and do not exceed the rated voltage range of your
meter (CD-77= 500V, Fluke=1000V). The readings should show a smooth climb in voltage. If there is a sudden or
fast drop in voltage right before the miss becomes apparent, the stator is usually at fault. If there is no indication of
the problem, it could be a small water leak in one or two cylinders.

6) Coils fire with spark plugs out but not in: Check for dragging starter or low battery causing slow cranking
speed. DVA test stator and trigger. Disconnect rectifier, regulator and retest. If the problem goes away, replace the
rectifier and/or regulator.

7) Engine runs rough on top or bottom two cylinders (4 cylinder engines): Check DVA voltage of the stator
between blue wires and to ground. Readings to ground should be fairly equal. If unequal, swap stator leads (blue
with blue/white, red with red/white) and see if the problem moves with the stator leads. If it does, replace the stator.
Check trigger resistance between #1 & #2, compare to resistance between #3 and #4. The readings should be
approximately 850 to 1250 for OEM (950 for CDI & Rapair). For test purposes only, swap trigger leads 1 & 3,
and 2 & 4. If the problem moves, replace the trigger. If it does not move, swap coil primary wires, and replace the
pack if the problem remains on the same terminals.
8) No fire on one bank (odd or even cylinders on Inline 6 cylinder engines): Check DVA voltage of the stator,
checking from each red and blue wire to engine ground. The readings should be approximately 180 volts or more
on the blue wires and 30 or more on the red wires. If a DVA meter is not available, swap both sets of the stator
wires between the packs. If the problem moves, replace the stator. If the problem stays on the same bank, swap
physical location and all connections of the two packs. If the problem stays with one pack, replace the pack. NOTE:
If the pack is bad, it is recommended that BOTH packs be replaced if the packs are not manufactured by CDI or
Rapair. If the packs lose ground, internally or externally, the packs manufactured by other sources usually have
severe damage to the bias circuit and have to be replaced as a set. The packs manufactured by CDI and Rapair will
withstand loss of ground connection, normally with no damage to the bias circuitry. In most cases you will just lose
fire.

9) Intermittent firing on one or more cylinders: Disconnect the white/black wire between the packs on a 6 cylinder
and retest. If all cylinders now fire, replace both packs as there is a problem in the bias circuitry. On all others,
check for low voltage from the stator and trigger. Disconnect the rectifier and retest. If the problem disappears,
replace the rectifier.

10) All cylinders fire but the engine will not crank and run: On 3 and 6 cylinder engines, disconnect white/black
wire and check the bias circuit (white/black terminals) resistance to engine ground. Readings should be
approximately 15,000 for standard packs and 9600 for racing units. If the readings are correct on the packs,
index the flywheel and check timing on all individual cylinders. If the timing varies, replace the packs. On 4 cylinder
engines the bias circuit is internal, therefore the only way to verify proper operation of the bias circuit is to index the
flywheel and check timing on each cylinder. If the timing is off replace the packs.

[us1]

Put timing light on each cylinder and rev the motor over 3000 RPM and then let it idle. See if at any time you loose spark. Tell me what happens and I'll tell you what to do next.

[Talon2.5]

hey john,

if you could post what is going on loosing spark through that rpm range that would be a great thing for us to print out ;)

[Greg Moss]

If when the rpm's exceed 2500 the timing light goes out the high speed windings in the stator are bad.

[Raceman]

The first experience I ever had with a cracked exhaust divider was that the boat idled fine, but it didn't want to get on top and lost about 8 MPH. This boat showed water on a couple of plugs and had one piston pretty clean on top. It may not be your problem, but it sure is easy to look in the spark plug holes. I always look there first for any non high perf Merc V6 that loses speed. I've seen several now, but never on one with a HD exhaust divider.

[B.Mac]

Timing light shows all cylinders have spark up & through 3500
and back down again. # 5 did have erratic/ on again- off again, then at times looked like a flashlight at idle:eek:, instead of the steady rythmic flashing the other holes showed @ idle. Looked closer to find spark jumping from end of coil tower to salty block (remember motor got swamped a little just before start of problems yesterday) Cleaned coil wire & reinserted into tower. #5 now firing correctly.

John I haven't tested the boat yet but is it possible to lose that much power from losing one cylinder:confused:? To where I can't even get a Vector up & out with a V-6? Does the dropping of a single cylinder take that much away from a V-6? I'm going to guess I got both bottom coils wet yesterday and possibly lost the two bottom holes and # 6 had time to dry off a little overnight enough to fire correctly on the light this morning? I guess I'll take all the coil high tension leads out, clean, & coat the coil towers with some kind of non-conductive schmutz and hope for the best? Lord:rolleyes: please let this be all it is! I guess I ought to clean up and coat my primary connections while I'm at it. I think West Marine has that waxlike anti-corrosion stuff ya spray on ya mota, guess it wouldn't hurt to spray somma that on there too. Whatta ya coat your wires with? I appreciate all & any feedback?

Thanks guys
B.MAC

[Greg Moss]

I use Permatex tune-up dielectric grease on all my crimp and push on electrical connections. In side sparkplug boots also. It really helps with the crip connections that always turn green and the wire falls apart. I also use it on all my trailer wire connections. The screw terminal connections I use liquid electircal tape from star brite. I don't know if you have a Mac tool man in your area but they sell a product called Howe's Lubricator that work GREAT for spraying the powerhead down.

[B.Mac]

Haven't water tested yet, but sounds a lot better on a hose.
Cleaned all primary connections of salt corrosion, new plug wires....Marine supply wants $60.00 for six-six inch wires.
Bought V-8 aftermarket metallic universals at Discount Auto Parts for $19.99.
A little dielectric schmutz here, a little liquid tape there, spray some wiredry on everything and spray a little Boeing T-9 in on #s 5&6 coils. Oh yea, new BU8H's. $4.49 each at Marine Store.....$1.19 at Discount Auto Parts. $50.00 should be good for another 6 mos. Wish it could all be that simple. Thanks John that timing light saved me alot of searching, and woulda probably got knocked on my keester:eek: pullin' the wires while idleing. Why do I always overlook the simple stuff?

Even jacked all the way up on the plate, my motor gets swamped coming off plane. I trim way up when coming off but still get wet from backwash. Guess that's the price of a V-6 & a Vector?

Thanks everybody

B.MAC

[us1]

Yes loosing one cylinder will take lots and lots of power from the motor. You might thing it would take 1/6 the power from the motor but it will take more like 1/2. Greg Moss pretty much covered all the rest of the questions like the Dielectric Greece and why you might loose spark over 2500 to 3000 RPM. I glad its working now.

[MERCMAN]

#5 is the worst cyl on a merc v6 to lose , when you lose 5 a merc v6 runs like a 9.9!!!!

[B.Mac]

Man what a difference a little T.L.C. makes to your electrical system! I forgot what this thing is suppose to run like. Since going through my electrical wiring & cleaning it up I must have picked up a few ponies because I'm hittin' 80 now w/ pedal to spare. All this talk about blowovers has got me spooked now :eek: (which is always a good thing). Water was weird today and at 80 I noticed a "lifting" in my bow that I haven't noticed before. Feels like air getting up under my bow and lifting in the front more. Got me nervous, maybe it was there before just didn't notice it. Oh well, I like being nervous.......keeps me from getting stupid. Thanks for your help fellas shes runnin' better than ever.

B.MAC

[us1]

Keep the dry side up;)

[skydog]

Bump,Very good post just wanted to get it back up to the top some very good info! Skydog

[200VEGAS]

im losing spark below 1000 on timing light on #4

[200VEGAS]

ttt. cant get over 3000 without 3 people leaning on front seat. also broke a driveshaft last weekend. got a different lower on there, now need to address the loss of power issue. had this problem last year, and i tjhink it was the stator. i put a used one on and it was fine for maybe 6 trips. i did get a dva last time so i will break out the timing light and the dva...