Boat Repair Questions? Ask a Marine Mechanic for Answers ASAP
that sounds good. can you explain the last sentence to me?is the black/yellow wire
coming from the stator to the screw terminal, or is it a wire on the pack? do i turn the
engine over as i check it? where do i check this? how much spark ? can i set the meter on volts or amps to test the amount of fire? what kind of problem in the kill circuit, and how do we test it? just as a brief overview; the motor revs up to 5000 or so then dies,
it then reaches around 3500 or so and revs again. once again dropping rpms. i have cleaned carbs, cleaned and checked fuel system, checked valve at motor where fuel
line connects, cleaned choke lines and tested, checked fuel diaphragms, connected fuel directly to carb lines and pumped ball, used electric fuel pump, replaced coils and spark plugs, tested temp sensor and oil sensor, disconnected wiring harness and ran without ignition switch. buzzer still sounds and she dies as explained. someone suggested it might be the rectifier. i tested the leads from the stator with the motor running by skinning a place on each brown wire. as the engine reached the magic rpm the voltage drops from around 125-130 down to 60 or so then recovers until it surges again.
After pushing the wire out of the connector plug the connector back in and try it, or use an ohm meter , with the main harness unplugged just pull the connector apart and check the black/yellow for continuity to ground, any reading means short. If stator , coils and everything else checks out then replace the pack. and does it have QL77JC4 Champion spark plugs in it? Or some other brand or non-resister type plug. and a correction the voltage from the stator should be 150 at cranking speed not at 5000 rpm.
i am familiar with the kill switch wire. it comes out of the pack but is not in a plug. it is black /yellow and is connected by waterproof buttsplice. i guess it was cut off earlier. i know it is the right wire because i ran it without it and the motor wouldn't cut off without
me hitting the chokes. my meter is standard and is set on ac volts. i did use a spark tester between the spark plug and the coils. i tested each one individually. they dropped the light at the magic rpm and picked it up around 3500 again up and down. each one was consistent, so i am sure it ain't the coils. without the light, grounded at the block they are strong and blue. the plugs are champion L77JC4 and are brand new. the plugs that are on the powerpack are: one; blue/white/green/purple. two; orange/orange-black, 2 yellows. no plug: there is the kill switch wire, the brown temp sensor? three orange---blue stripe-top coil--solid center coil--green stripe--bottom coil and the black ground under the mount bolt.i think the voltage is around 60 to 70 on browns at crank over. it has been a while, i don't recall exactly.
The only way to read the voltage from the stator is to use a peakreading voltage adapter, the stator puts out a/c voltage and the adapter averages out the positive and negative peaks in votage to give you a steady reading. The meter set on a/c volts cannot read this because it happens to fast. check the stator like I suggested with an ohm meter.The blue, white ,green and purple wires are the trigger leads.
I see that you mentioned a horn going off, is it going in and out of slow (speed limiting overheat warning) maybe? If the temp switch lead is solid tan, it may be the case that there is some calcification in the cylinder head causing a hot spot, the new temp switch is less sensitive to this and has a tan wire with a blue stripe. There was a service bulletin about that a long time ago.
If you have good spark and it is not going into S.L.O.W. then the problem is elsewhere, were the carbs disassembled cleaned and adjusted properly? Debris floating around in the float bowls can block the high speed jet and when the motor slows, it can fall away, the rpms pick back up and it gets sucked back to the jet, does it run rough when the rpms drop or still sound like it is firing on all three? On a motor this old the fuel lines can come apart on the inside and a flap fall into the fuel stream partialy blocking it off, check the fuel hoses on the motor, are they rock hard or mushy feeling? replace them. This is a problem that show up even more now that we have ethanol in our gas.
Another trick is to hook up a timing light and look into the carb throats with the engine running at speed and watch the fuel that is coming out of the main nozzle, you can almost count the drops of fuel as the light is like a strobe light and stops motion. look for the amount of fuel to lessen or stop and pick back up as the motor surges.
it starts and runs great at idle and all the way up to the drop out rpm. it is running fine on the low end when it drops. it is rapid like-----vroom 1secdrop---vroom 1sec drop.. maybe
that explains it. its like it is programmed to die at that rpm, almost as if it is cut off and one second later restarted over and over. but like i said, when it does, the spark plug light is showing light off at the one second interval, then on as it revs, then off for the one second, then on and so on. it will do it in or out of gear, with or without the wiring harness connected. i thought originally it was a sensor. but, even with the oil sensor and the temp sensor disconnected or shorted to ground it does the same thing. that would indicate a fire issue and not fuel wouldn't it? if the stator is bad can it cause this as it gets hot and shorts out at high rpm or not? thanks for the input and i will try the tests on the stator in the am. you mentioned disconnecting the kill switch wire, do i turn it over with ignition and test? if so, which wire do i test for spark? do i take the plugs out during the test?
Yes you would disconnect the the black/yellow at the pack and test for spark at the coil leads, but you stated that you have already run the motor with this wire disconnected from the pack right? If not then disconnect it from the pack and run it to see what changes if anything. If the problem goes away with the wire disconnected then there is a short in that wire somewhere. and you will have to short out the black/yellow from the pack or use the choke to stop the motor.
It has been my experience that when a stator shorts out when it gets hot, that the motor will die and then will restart after the stator cools. The stator supplies a/c voltage to the pack and it is rectified to d/c voltage and stored in a capacitor, voltage from the trigger tells the pack to release the stored voltage to the coil on the cylinder that is supposed to be fired, if you check the stator, triggers and ignition coils with an ohm meter and all check good then something may be going on in the pack. It could also be heat related and would happen faster than in the stator. Thats the way you troubleshoot this ignition system, if everything test good then replace the pack, there is no test for it except output voltage to the primary coil wire.
A fuel related surge can happen quickly also, I would not rule it out until I have looked at the fuel delivery with the timing light, while the motor is running. I can get you the specs for the triggers, and the ignition coils , but i doubt it has anything to do with the coils. Check for 35 to 45 ohms between the white and blue, white and green, white and purple. With the plug disconnected from the pack and using the pins or sockets in the connector. Ignition coils are 0.2 to 1.0 ohms on the primary and 200 to 300 ohms thru the spark plug lead.
FROM STATOR: COILS:
ORANGE PAIR-----535.2 OHMS 245.1 OUTPUT .2 INPUT TOP
BROWN PAIR------525.2 OHMS 244.4 OUTPUT .3 INPUT MIDDLE
YELLOW PAIR---------1.7 OHMS 246.2 OUTPUT .2 INPUT BOTTOM
PURPLE/WH----------10.8 OHMS POWER PAK:
GREEN/WH------------10.8 OHMS 94.9 BLUE/WHITE
BLUE/WH---------------10.8 OHMS 92.6 GREEN/WHITE
WHILE CRANKING MOTOR; 105.3 PURPLE/WHITE
ORANGE PAIR----119.5 VOLTS AC
BROWN PAIR-----139.8 VOLTS AC
YELLOW PAIR------10.2 VOLTS AC
WHEN THE KILL SWITCH WIRE IS CONNECTED OR DISCONNECTED THE ENGINE STILL BEHAVES THE SAME WAY WHILE RUNNING. I HAVE ANOTHER
POWERPACK. I TESTED IT THINKING TO PUT IT ON THE ENGINE FOR A TRIAL,
THE RESULTS: PURPLE/WH--146.9...GREEN/WH--86.8...BLUE/WH--227.5. I GUESS THIS IS A NON WORKING PART, CORRECT? TELL ME YOUR OPINION. I THINK IT
IS TIME TO GIVE UP ON THIS THING, OR TRY ANOTHER PACK.
WE ARE NOW TAKING THE PLATE OFF THAT ALLTHE ELECTRONICS ARE MOUNTED TO TO SEE IF THERE ARE ANY SKINNED OR BURNED WIRES BEHIND THE MOUNT PLATE THAT COULD BE SHORTING OUT. WILL ADVISE. THE WIRE TO THE TEMP SENSOR AND THE TEMP SENSOR ARE SOLID BROWN. NO BLUE STRIPE. STILL HAVE BUZZER. WITH THE WIRING HARNESS DISCONNECTED KILL WIRE HAS NO CONTINUITY TO GROUND AND NO READING, AS SOON AS HARNESS IS CONNECTED THERE IS CONTINUITY BUT A 0.00 READING. ALL THE WIRES BEHND THE MOUNT PLATE, EVEN THE TRIM WIRES TO THE RELAYS LOOK OK AND ARE SEALED UP TIGHT. NO PINCHES OR SKINNED PLACES
THE 10.8 WAS OHMS ON THE PLUG THAT COMES FROM THE STATOR.USING THE WHITE AS ONE PIN AND TESTING ALL OTHERS WITH THE WHITE. BOTH THE
MAIN INPUT PLUGS WERE DISCONNECTED. THE ONLY THING THAT WAS CONNECTED WERE THE WIRES TO THE COIL AND THE KILLSWITCH WIRE.
DOES THAT MATTER? IF SO I WILL DISCONNECT ALL AND TRY AGAIN. YES I DID
ALL THE SHORT TO GROUND TESTS ON ALL BROWN AND ORANGE WIRES WITH ONE LEAD IN EACH INDIVIDUAL WIRE AND ONE WIRE GROUNDED TO
THE BLOCK. THEY ALL READ 0.00 ON OHMS. I TRIED THE OTHER PACK AND
THE ENGINE WON'T EVEN START USING IT. I FIGURED THE READINGS I GAVE
YOU EARLIER ON THE TRIGGERS WOULD BE THE REASON WHY. WHAT NOW?
I AM READY TO LIGHT A MATCH
THANKS, XXXXX XXXXX NOT FIND A STATOR THAT FIT, NOR COULD WE FIND A
TRIGGER ADVANCE. I ASSUMED IT WAS BAD FROM THE READINGS. A LOCAL
MECHANIC HAD A POWERPACK TO FIT A YEAR OLDER 70. I USED IT NEW
OUT OF THE BOX (NO CHARGE) AND RAN THE BOAT WITH IT TEMPORARILY
CONNECTED. THE ONLY DIFFERENCE IS THAT IT DID NOT HAVE QUICK START
LEADS, LIGHT BROWN LEAD (TEMP?), AND THE REV LIMITER. BASED ON WHAT YOU SAY HERE AND HAVE SAID, YOU WERE CORRECT. THERE WERE NO OTHER PROBLEMS WE COULD FIND. SHE RAN LIKE A RAPED APE, EVEN ON
YEAR OLD FUEL. THE ONLY ISSUE (6800 RPMS, I PULLED HER BACK). WE ARE ORDERING THE RIGHT PACK TOMORROW. I GUESS THE REV LIMITER IN THE OLD PACK WAS BAD. THANKS AGAIN. I WILL FIGURE OUT HOW TO ADD A BONUS TO THE PAY AND SHOOT IT IN TOMORROW.