Overcharging 18 volts

[Wonbigfish]

I have a 1997 90hp Force Outboard on a 16.5ft Palm Beach. Went out fishing Saturday on Mosquito Lagoon. Boat was kinda tough to keep running. Managed to get on a plane & make it back to boat ramp. I noticed on my depth finder voltage was over 18 volts. My question is would a bad voltage regulator cause motor to run rough? Could a bad voltage regulator cause damage to stators. Will changing a bad regulator effect how the motor runs?
Please Advise
Wonbigfish

 

[alldodge]

Re: Overcharging 18 volts

No outboard expert here but from my research it could either be a bad battery or regulator. If the battery is weak the charging system will put out more juice. If the battery is weak the drain can cause reduced spark causing roughness. Pull the battery and load test it.

 

[Jiggz]

Re: Overcharging 18 volts

Your engine model has a regulated charging system. The fact that the finder indicates 18 volts, it could be an indication you have a bad regulator. Supposedly, this should not affect your engine ignition system since it is totally different ckt. However, the charging coils are also located on the stator which also provides power to the engine ignition system, which can be affected. Troubleshoot by temporarily disconnecting the regulator off the ckt and see if the engine performance improves. If it does, it's time to replace the voltage regulator/rectifier unit.

 

[pnwboat]

Re: Overcharging 18 volts

If you're seeing 18 volts, then the first thing that I would suspect would be the voltage regulator. Can a bad regulator/rectifier affect the ignition system? Yes, it can. It's one of the first things to check for an engine ignition miss.

Can a bad regulator damage the stator windings I guess it could.

One thing that I've noticed on the late 1990's motors that use the regulator/rectifier is that the bullet connectors on the yellow stator battery charging wires that connect to the voltage regulator/rectifier often look burnt and discolored. Looks like they've been overheated. I've replaced a number of the bullet connectors with a terminal strip type connection. Never seen the problem again. I suspect that the bullet connectors are not heavy enough, or after a while, the connection is less than ideal generating excessive heat.

Just a note, most of the Force motors are stator driven ignition systems. That is, the ignition voltage is generated by the stator. No battery is necessary. The only thing the battery does is supply voltage to the starter and accessories. You can pull start the motor with just a rope around the flywheel without any battery connected. Once the flywheel is spinning, that's all that is needed to generate spark to the plugs. The only exception to this is the late model Force 5 cylinder motors. Some of them do have a battery dependent ignition system.

 

[Wonbigfish]

Re: Overcharging 18 volts

I always top off my battery the nite before with a 2 amp trickle charge & check battery connections. I did notice on the regulator a line across from mounting hole to almost the other mounting hole. The neoprene on this unit is black so I can't see anything inside it. The line could be a burnt wire or just a thin abrasion. I plan on replacing the regulator before this week end's flats trip. Thanks to all for quick feed back. BEST WEBSITE
Wonbigfish

 

[oldboat1]

Re: Overcharging 18 volts

After you replace the regulator/rectifier, don't run the engine without the battery connected.

 

[Wonbigfish]

Re: Overcharging 18 volts

Replaced voltage regulator. Can't seem to keep it running. It will start & run in upper rpm's but runs rough. When I return to idle it shuts down sometimes with a backfire. It will start at idle and run smoothe for maybe 2 - 3 seconds and shut down as if I turned thr key off. I did check voltage via my depth sounder and the voltage problem appears to be fixed. Not quite sure what to check next. Any advise is appreciated.
Wonbigfish

 

[mklearl]

Re: Overcharging 18 volts

Backfire can indicate it's running too rich. Runs in upper rpm's it is using the gas. Lower RPM engine floods and dies. There is a good tutorial in the sticky section about timing and carbs. Check it out!

 

[pnwboat]

Re: Overcharging 18 volts

Sounds like you had two problems that were not related. Bad regulator and rough running. You've got the regulator issue taken care of, so now on to the rough running.

Double check your compression. Ideally it should be 120LBS or more. 100LBS would be the absolute minimum. Check and make sure the carburetors are clean and not gunked up. You can remove the fuel bowls and see if there is any crud in them. If you don't have a fuel filter between the fuel pump and carburetors, install one or replace the existing one.

If the carburetors check out OK, then take a look at the fuel pump diaphragm. You can kind of test to see if the fuel pump is working by squeezing the primer bulb to see if this helps. If it does, then the fuel pump diaphragm may have a tear or has gotten too stiff and hard.

Your motor has a fuel enrichment solenoid that functions as a choke. It's only supposed to let extra fuel into the intake when you push in on the ignition key. If it is leaking and dumping fuel into the intake, the motor will run too rich and may stall at low speeds. You can pinch off the small hose that goes from the carburetor fuel bowl to the solenoid to see if this has any affect.

Last but not least, take a look at the reed valves. The 1995 and later reeds are known to crack and break. The motor will not run very well if one of the reed petals is cracked or broken.

Forgot to mention to check for good spark on all the plugs.

 

[Jiggz]

Re: Overcharging 18 volts

If it runs smoothly for 2~3 seconds and dies thereafter, there is a good chance you have fuel related problems. Follow PNW's lead with regards to the carbs, fuel filter between the fuel pump discharge and carb inlet using a clear fuel filter or those so called see-through filters (probably the best investment for fuel related troubleshooting) and of course the fuel pump itself. With the clear filter, it makes it very easy locate the source of fuel related problems. If the filter rans out of gas (or stays low below 50%) while running the engine, it tells you the problem is upstream of the filter, i.e. fuel pump, fuel hoses, primer buld, suction tube, tank vent, etc.

If the fuel filter does not ran out of fuel and stays at least 75% full, then the problem is most likely downstream of the filter, i.e. bowl inlet tube restricted, float stock in up position, clogged jets, etc. The only thing that could also cause rough running that is not fuel related are the reed valves.

 

[Wonbigfish]

Re: Overcharging 18 volts

Carbs rebuilt with ethanol tolerant kits last year. Bulb is hard & inline fuel filter is full. The way it abrutly shuts off leads me to think an ignition component is failing. How can I check stator & coils.
Please Advise
Wonbigfish

 

[Frank Acampora]

Re: Overcharging 18 volts

Check your plug wires and spark plugs.. You sound like classic fouled plugs and possibly one or two bad wires. Fouled plugs WILL fire at high speed but misfire at idle. Once you get it to run correctly, check the idle speed Too low an idle speed will cause stalling. Now: The question is why is the idle too low? If the engine is only running on 2 cylinders, then of course idle speed will be too low. Correct the problem and idle speed will increase to specs.

Did you check compression ratio? It is possible that rough running and stalling has nothing to do with the fuel or ignition. You may be carrying around a dead piston.

 

[Jiggz]

Re: Overcharging 18 volts

Carbs rebuilt with ethanol tolerant kits last year. Bulb is hard & inline fuel filter is full. The way it abrutly shuts off leads me to think an ignition component is failing. How can I check stator & coils.
Please Advise
Wonbigfish

The easiest way to check for ignition problems is to do a spark check using a spark tester. By isolating which cylinder is not firing you can start a more focused troubleshooting. Again, a compression test is mandatory to ensure you don't have a dead cylinder.

 

[Big Fish Billy]

Re: Overcharging 18 volts

I pasted in a reply from RRitt on another thread...on my 1997 Force 40...I replaced my battery and the charging is at 14 volts, down from 18...

"Now - about that overvoltage & charging thing:
The battery is your voltage regulator.
If you have overvoltage at engine then there are only a few possible causes.
#1 is that you have your meter set to AC. AC voltage measurement is different from DC. Your boat runs on DC electricity and you need to keep your meter on DC.
#2 is that there is something wrong with your wiring or connections. If the battery cable is too long or if some of the connections are corroded then the engine has to put out extra voltage to compensate.
#3 is that your battery is bad. Just measure the voltage across battery terminals making sure to contact the actual battery posts. "

 

[submariner1980]

Re: Overcharging 18 volts

The battery is your voltage regulator.

False statement. The battery is the load for alternator.
Overcharging with high charging voltages generates oxygen and hydrogen gas by electrolysis of water, which is lost to the cell and destroy battery. Periodic maintenance of lead-acid batteries requires inspection of the electrolyte level and replacement of any water that has been lost.

 

[Wonbigfish]

Re: Overcharging 18 volts

Tried to start it today to warm up. Only got a back fire. I now have no spark. How can I test stator and or trigger. Are they both the same unit? I pulled fly wheel to visual inspect. Windings are plastic coated & don't show any obvious signs of faliure or hot spots.
Please Advise
Wonbigfish

 

[pnwboat]

Re: Overcharging 18 volts

The stator and trigger are two different units.

This is the stator. The White/Green and Green/White wires generate the ignition coil voltage. The two yellow wires generate the battery charging voltage.



Disconnect the Green/White and White/Green wires that come from under the flywheel at the bullet connectors. Use an Ohm meter and measure the resistance between the Green/White and White/Green that come out from under the flywheel. Should read 500 - 700 ohms.

This is the trigger. You cannot measure resistance of the trigger assy. on the 1996 - 1998 motors because they use an electronic Hall Affect circuit.

 

[Wonbigfish]

Re: Overcharging 18 volts

Put the meter on white/green & green/white 675 ohms. It looks new. Is there a bench test for trigger? The trigger is a lot less money. Thanks pnwboat.

 

[pnwboat]

Re: Overcharging 18 volts

Not saying that triggers don't go bad, but they're generally a low failure item. Don't know of any way to bench test them. You can use a DVA and measure the output voltage on the trigger wires as you crank the motor. You should see a minimum of 1.5 volts.

Disconnect the black yellow wire from the wiring harness. This is the ignition kill circuit. If spark comes back then you know the problem is in the Kill circuit/wiring.

If no affect, disconnect the 4 pin modular plug to #1 CDM/coil. Crank it and see if you get spark on #2 and #3. If no change, plug it back in and do the same with #2 CDM/coil. If after disconnecting the modular plug to one of the CDM/coils, spark is restored to the other two, then you know that the one that you disconnected is bad and preventing the other two from firing properly.

 

[Wonbigfish]

Re: Overcharging 18 volts

Home Run. It was the ignition kill circuit. I do recall getting zapped by my kill switch. I think I just might have got off easy on the 2nd problem.
Thanks to all. I did all the other checks & test and it came down to a safty kill switch.
Wonbigfish