Hello all
I just replaced the reeds in this motir and when I removed the intake and reed blocks there was chocolate milk in the bottom of the crankcase. Had to wait a few days for parts and when I returned to work on it the milk was gone. I went and did a test run and now the boat wont run right at all.
She fires right up and idles well now but when I attepmpt to give throttle it will be very slow to respond and then will take off well but then boggs down then will take off again. Then will bogg down and die.
Im sure its seperate problems but it all happened at same time.
Any help is very appreciated
The "chocolate milk" is usually oil mixed with water.
Sounds like moisture got in somehow.
The poor running:
The bogging could be the primer system is feeding to much fuel to the motor.
Pinch the hose to the primer after the motors been started.
Run better?
Then check the fuel pump and see if the diaphragm has holes?
That also might be there is an air leak somewhere?
A can of starting fluid, spray the intake side, around the carb and the area under the ignition.
Make a change in the way it runs?
One little backfire can blow a gasket and let the motor suck air and run bad.
The jets might be clogged?
Was working on a 97/120 had a miss and couldn't find it.
Cleaned the carb 3-4 times and all of a sudden the clog/miss was gone???
Didn't do anything different, just ran better after the 3/4 time the carb was cleaned??
Thank you sir. I will grab a can of starting fluid and check for leaks and clean the carb and retest and get back with results.
The milk in crankcase was only maybe a shot glass worth so could it just have been condensation? I did compression check and have 120-125 psi in all 3 cylinders.
Ok I pulled carb and cleaned and reset float (it wasnt right) pulled pump apart again and everything is good with it. Found an exposed wire from trigger to white wire that goes to bottom coil. All the wires insulation were very hard and crumbling. I replaced the wires from trigger as far back as I could get. Dont have tools to pull flywheel. Then ran engine in a barrel and got it up to 3000 rpm and it will surge from 3400 down to 2700. Only surges when I use throttle controls when i use throttle on carb only it revs fine and is consistant no surging. Im thinking its a bad trigger that only shows at higher rpm. Tried to test ohms but would not get any reading at all. Also yried with white/green to green white wires from stator and no reading either. Yellow wires would read 6.5 on ohms not sure what that means its a cheapo tester but it would steadily drop down to zero fairly quick. Im no electricion and confused.
Please help
The next 2 post have test info from outboatdignition.com
What you use depends on the ignition system you have???
Three Cylinder Engines
Mercury Designed Ignitions
1992-1997
Engines Using a Single Switch Box and Three Ignition Coils
No Fire At All:
Disconnect the black/yellow kill wire AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
Check the stator resistance and DVA output as given below:
Motors with Black Stator
Wire
Read To
Resistance
DVA
Blue
Red
Engine Ground
Engine Ground
3250-3650
75-90
180V or more
25V or more
Motors with Red Stator
Wire
Read To
Resistance
DVA
White/Green
Green/White
500-700
180V or more
Red Stator Adapter
Wire
Read To
Resistance
DVA
Blue
Engine Ground
Open
180V or more
No fire or Intermittent on One or More Cylinders:
If the cylinders are only acting up above an idle, connect an inductive Tachometer to all cylinders and try to isolate the problem cylinders.
Check the trigger resistance and DVA output as given below:
Wire
Read To
Resistance
DVA
Brown wire (#1)
White wire (#2)
Purple wire (#3)
Brown wire (#1)
White wire (#2)
Purple wire (#3)
4V or more
4V or more
4V or more
1V or more (a)
1V or more (a)
1V or more (a)
This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no fire on one cylinder and the DVA trigger reading for that cyli?lder is low — disconnect the trigger wire and recheck the DVA output to ground from the trigger wire. If the reading stays low — the trigger is bad.
Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least 150V or more at both places. If the reading is low on one cylinder, disconnect the green wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.
Engine will not rev beyond 3000-4000 RPM:
Connect an inductive Tachometer to all cylinders and try to isolate the problem. A single cylinder dropping fire will likely be the switch box or ignition coil. All cylinders acting up usually indicate a bad stator.
Connect a DVA meter to the stator’s Blue wire and do a running test. The DVA voltage should jump up to well over 200V and stabilize. A drop in voltage right before the problem occurs indicates a bad stator. (Blue to Engine GND if the engine has a Red stator kit installed).
Connect a DVA meter to the Red wire. The DVA voltage should show a smooth climb in voltage and remain high through the RPM range. A reading lower than what is on the Blue wire indicates a bad stator.
High Speed Miss:
Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the switch box or ignition coil. Occasionally a trigger will cause this same problem. Check the trigger as described above under “No fire or Intermittent on One or More Cylinders”.
Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Engines Using a Combination Switch Box and Ignition Coil (CDM Modules)
No Fire At All:
Disconnect the black/yellow kill wires from the harness and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
Disconnect one CDM module at a time and see if the other modules start firing. If they do, the module you just unplugged is bad.
Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
Check the stator resistance and DVA output as given below:
Wire
Read To
Resistance
DVA
White/Green
Green/White
500-700
180V or more
o fire or Intermittent on One or More Cylinders:
If the cylinders are only acting up above an idle, connect an inductive Tachometer to all cylinders and try to isolate the problem cylinders.
Using a set of piercing probes, check the trigger resistance and DVA output as given below:
Wire
Read To
Resistance
DVA
Purple wire
White wire
Brown wire
Engine GND
Engine GND
Engine GND
Open
Open
Open
3V or more
3V or more
3V or more
NOTE: These triggers have the bias circuitry built into them, therefore you cannot measure the resistance like you could the older engines. In addition, there are four triggering coils used.
If # 1 is not firing, disconnect #2 CDM module and see if the #1 module starts firing. If it does, the module you just unplugged is bad. If it does not, disconnect #3 CDM module and see if the #1 module starts firing. If it does, the module you just unplugged is bad.
If # 2 or #3 are not firing, swap locations with #1 and see if the problem moves. If it does, the module is bad. A continued no fire on the same cylinder indicates a bad trigger.
High Speed Miss:
Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the trigger or CDM module.
Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Also adjusting the air/fuel mix screw on the carb might help.
There are some good video's on U-tube
Guy FrankA or Frank Amphora put out some good videos.
Ok I havent been able to get the dva adapter for my meter but i disconnected the yellow wires from stator to rectifier and the engine fires up no problem. The tach does not work with the yellow wires unplugged though. So per the above posts I need a new rectifier correct? Would running the engine with a bad rectifier cause other parts to fail?
Im really not good at all with this electrical stuff. Espeacially the terms and reading the instructions makes my head hurt. Haha should all these tests be done with engine running at a high rpm or not running? My engine has a red stator but not sure if or where the switchbox is. Where should it be?
Im sure I can do the work just need some help with explaining some of the terms in instructions.
Your ignition could be 2 different styles??
One has a component 2-3"X 5-6" and called a switch box or CDI.
The other just has coils that take the place of the box.
You have the serial# or model# ??
Or, pics of the ignition.
Sometimes the tach can go bad and cause the motor to run bad or not at all.
Running with a bad rectifier shouldn't hurt anything.
Since it runs without the tach, hook a volt meter to the battery and check/record the voltage as you start
and operate the motor.
Voltage should drop as it starts and then go back to the initial setting or if charging it should increase??
Ok my engine has 3 coils I wasnt sure if the switchbox was something besides that. I had checked the voltage at battery when running with rectifier hooked up and is was at 14.5 at 3000 rpm. The volt meter on dash was pegged at 18volts though. And tach was working. When I unhooked yellows from stator to rectifier the voltmeter on dash was at between 13 and 14 and tach did not work.
Serial # 0E325369
All I see is the stator, trigger, and 3 coils as far as ignition parts I recognize.
I got the flywheel off today and inspected the stator and it looks perfect. No cracks or burn spots anywhere. I tried the resistance test again and get nothing from the green/whit to white/green wire. Is my stator bad? Still get 14.5 volts at battery when I was running it yesterday.
Got to the trigger and the wires were all corroded with insulation cracked and crumbling off. Wires under insulation have a green/brown look to them. Looks very bad. Trigger also has some cracking at the inside edge and looks like a burst bubble in one spot. I cant imagine this is normal.
So I got my new trigger installed and still have the same issue. Running it in a barrel today and I put it up to 3000 rpm with the hand control and would stay at that rpm for a few seconds then rev up to 4000 then surge up and down 3-700 rpm then drop down velow 3000 then back up.
Im lost and frusterated. Any other suggestions Jerry?
Sorry it took me so long to get back to this.
Turns out I had air leaking into fuel line causing a very lean condition. Replaced all fuel line and clamps along with the new trigger and its running well again.
Having a new issue now will start a new thread.
