120HP Force charge problem

[floatfan]

I've cleaned a the carbueretor a few times on my 9.8 Merc and replaced the foot oil a time or 2, but that's the extent of my outboard repair knowledge, so be gentle with your technical talk.

Took my 18' bowrider with a 1995 Force 120 out Saturday for a cruise around the lake. Started out with a fully charged battery. Rode the lake for approximately an hour and 15 minutes at near full throttle. Killed the motor and when we went to restart it, it didn't have enough juice to turn it over. We weren't running a radio or any other electrical anything. Had enough power to raise the trim thankfully. Ended up having to get a tow back to the dock. I really didn't pay much attention to my volt meter, but I THINK I remember it reading between 12 & 14 volts while under way Saturday. I think my battery is fine because it takes a charge from the battery charger fine.

From what I understand, the Force has a stator system. Rather than just replacing everything in a trial and error way, is there any way I can test the system to see if the stator is working and sending a charge? I have a voltmeter I can hook up to it to see output...but I don't know what to look for or where to test it.

ANY suggestions are welcomed and appreciated!

 

[foodfisher]

Re: 120HP Force charge problem

Take the battery to an auto parts store and have it load tested.

 

[pnwboat]

Re: 120HP Force charge problem

If the battery checks out OK then proceed with the following steps. Charging system is pretty straight forward. There should also be a fuse mounted on the coil plate. Make sure it's good. There is a battery charging winding in the stator that generates A.C. voltage to the Rectifier/Regulator assy. which then feeds D.C voltage to the battery. With the engine running, you should see approx. 16 volts A.C. on the two yellow wires that come from the stator to the Rect./Reg. assy. If not, stop the motor and disconnect the two stator wires that go to the Reg/Rect. assy. I believe they are yellow. Measure resistance between the two. You should see very low resistance, .6 to 1.1 ohms. If not, then the battery charging coil in the stator is bad. If everything checks out OK, then measure the output of the Rect./Reg. assy. Start the motor and measure D.C. voltage output on the red wire coming from the Rec./Reg assy. It should be approx. between 13.5 and 14.5 volts D.C. If not, the Rect./Reg. assy is bad.

 

[floatfan]

Re: 120HP Force charge problem

Thanks for that. I'll check it soon. I noticed that my tach would work sometimes Saturday and sometimes it wouldn't, but I just figured my tach was going bad. After reading some of the other threads here, I see that switching the 2 stator wires around could rectify this problem (for reasons unknown)...and was wondering if this could also be the cause of my charge problems?

 

[pnwboat]

Re: 120HP Force charge problem

As far as I know, the tach fix is done on systems that have a rectifier charging system. You should have a Rectifier/Regulator charging system. Also if you have a gray wire coming off of your Rect/Reg. system, that is the tach signal. If your Rect./Reg. is bad, it may affect the tach.

 

[floatfan]

Re: 120HP Force charge problem

My Seloc Force service manual I bought off Ebay on Tuesday arrived today (awesome seller!). With the advise I received on here paired with my trusty manual should allow me to get this problem fixed this weekend. I'll update y'all on my findings.

 

[floatfan]

Re: 120HP Force charge problem

I finally found the time to get out there this past weekend and do a little tinkering. I had the battery on the trickle charger all week and it shows full charge. I first tested it with my voltmeter and it shows a charge of 12.6 volts. Seems good, but I took it out of the boat and took it to Advance Auto for a load test. Battery shows good. Installed it back in the boat and the motor won't turn over fully. Acts like a dead battery...not enough juice to turn over, but again, the battery shows 12.6 volts and seems to be fully charged. All battery connections are tight and clean. I took the cowling off the motor and was a bit perplexed. I did realize the problem with my tach. Seems that when whoever was installing the plate that has the wires on it to the motor, the tach wire got mashed (nearly severed) behind one of the bolts. I removed this and spliced the wire, so that should fix my tach issue.

Ok fellas...where do I go from here. My battery checks out completely...and is rated as 800CCA. Why would it seem to be sluggish when trying to crank? What is my next thing to check regarding the reason it didn't charge?

 

[pnwboat]

Re: 120HP Force charge problem

As far as the cranking problems are concerned, you either have a bad starter, or something in the starting circuit bad. To eliminate anything in the starting circuit, you can take a set of good jumper cables and connect one end to the battery. Some of those cheap thin jumper cables w/cheap clamps will not pass enough current to make the starter work like it should. Make sure the ignition key is in the OFF position. Connect the negative cable of the other end to the engine block. Take the remaining positive cable end and briefly touch it to the battery connection on the starter. Starter should engage. You'll see a pretty good arc when you touch the cable to the battery connection on the starter. This is normal. If the starter still turns slowly, then it's bad. If it turns over as normal, then you either have a bad battery cable, or bad battery cable connection, or maybe a bad starter solenoid. Bad connection is pretty common. Connection may look OK visually, but corrosion builds up underneath the battery connection and prevents a good contact. Check and clean both positive battery cables on the starter solenoid and the starter itself. Also clean the negative cable where it is connected to the engine block.

Once you get the starter problems fixed and the engine running, you can trouble-shoot charging issues per instructions in post #3. Who knows, you're starting and possible charging issues may be due to a bad battery cable or cable connection.

 

[floatfan]

Re: 120HP Force charge problem

Just as an update...what I thought was a charging issue was simply a bad starter. So my gauges were right...14volts while running. $65 starter rebuild and I was good to go. Thanks for all the suggestions.