1993 Force 70 Not Charging

[cmblackburn]

I have a 1993 Force 70 that is not charging my battery. I am using a fluke DMM to read my readings. I have measured the resistance of my charging coil on the stator and according to the clymer manual it reads fine, its reading less than 1 ohm. I read the AC volts coming off the coil and its only reading between 6 and 7 Volts AC. I checked the DC coming off the rectifier and its reading is only 12.5 Volts DC when the motor is running and 12.9 when I turn it off. I am leaning towards the stator being bad but wanted to get some expert advice. Thanks for any replies.

Also what is the easiest way to get the flywheel nut off?

Thanks
Chris

 

[Barnacle_Bill]

Re: 1993 Force 70 Not Charging

Test your rectifier. The procedure is in your manual.

I use an impact wrench for flywheel nuts.

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

Thank for the info, rectifier tests good according to manual, any other suggestions?

 

[pnwboat]

Re: 1993 Force 70 Not Charging

You should be reading more like 13 - 15 volts AC from the stator.

Flywheel can be stubborn even after you remove the nut. Once you remove the nut, spray some WD-40, CRC or something similar. You probably will need a flywheel puller.

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

13 - 15 Volts is that with a regular DMM or do I need a DVA to be able to check it?

 

[pnwboat]

Re: 1993 Force 70 Not Charging

A standard DMM is all that is needed to measure the AC voltage output of the stator going to the rectifier.

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

Ok thanks. I guess my stator is bad then, even though it measures the correct resistance.

Thanks for all the help.

 

[pnwboat]

Re: 1993 Force 70 Not Charging

One thing I wanted to mention. When you take your measurement, you need to measure across the stator coil. That is, place each probe from your DMM on each of the wires coming from the stator. Do not take measurements from stator terminal to ground. If you do, it appears that you'll only be reading half the voltage. I double checked on my motor. I have 16 volts AC, reading across the AC terminals on the rectifier. If I try with one probe on the AC terminal and the other on the engine block, I only read 8 volts AC.

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

Ok thanks. I checked across them and only getting about 7 Volts. I have read online that I should change the rectifier the same time as I change the stator, is this really necessary?

 

[pnwboat]

Re: 1993 Force 70 Not Charging

It's not absolutely necessary to change the rectifier if it checks out OK. Just cheap insurance to minimize any future problems. Rectifiers are relatively cheap considering the cost of being left stranded due to a bad one.

 

[bertthedefender]

Re: 1993 Force 70 Not Charging

I have read online that I should change the rectifier the same time as I change the stator, is this really necessary?

I've read that too - I think the reason given was that a fault with one can take the other out.

I replaced the stator and rectifier with Rapair parts on my 70hp (part nos: Stator 174-8778K1, Rectifier 194-5279). And it fired right up. There was a problem with the rectifier however, producing 17-18 volts at anything above idle and that part was replaced under warranty but I've yet to fit it. The motor is currently running a generic rectifier that was very cheap but has worked faultlessly, producing an ideal 14.4v at the battery. Doesn't have the grey wire for driving a tacho though. (I also have a rectifier from a quad bike which was cheap and works perfectly well)

In my case both stator and rectifier were shot. Stator was original black model which had burned out low-speed coils and the rectifier failed the diode check. Result: no ignition at all.

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

Where's a good place to buy a new stator? I thought about buying a used one on ebay for about $35 but I am kinda worried about buying a $35 broke one like I already have.

Also what is the best way to hold the flywheel to get that nut off?

 

[bertthedefender]

Re: 1993 Force 70 Not Charging

I removed the flywheel using an air impact wrench and the flywheel didn't need to be held. Once you've got the nut off you'll need a flywheel/harmonic balance puller and some 5/16" UNC bolts to fit into the three holes on the flywheel. I also used the impact wrench on that to break it free. If you are using a mallet to loosen it, be careful not hit the edges of the flywheel and dislodge any of the magnets that run around the inside. When you are ready to lift the flywheel clear, make sure you recover the flywheel key that slots into the end of the crankshaft.

When fitting a replacement stator be careful to put it on in the same orientation as the original.

Refitting the flywheel takes more effort as it must be torqued to 90 ft lbs and therefore must be held fast. You can buy a tool to hold the flywheel, but if you're careful you can get away with a large screwdriver positioned into the teeth of the flywheel and locked against the starter motor bendix.

Have you checked both charging coils on your motor? The stator has two coils, one for speeds <2500rpm and one for >2000rpm. Does the motor run ok? Do you get the same low voltage at the battery at low and high engine speeds? In my case the low speed coil was shot so would not produce enough power to fire up the engine at cranking speed. It sounds as though yours isn't that bad yet.

Looks like iboats sells the stator you need:

http://www.iboats.com/mall/partfinder/?*******=291154198&gd_grid_id=1277&gd_poid=334755&gd_row=15&keywords=stator&**********=128185271

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

The motor runs the same as it always has, really good. Just will not charge the battery at all.

I have a friend who had an electric impact gun I will try it to see if it will get the nut off for me.

 

[cmblackburn]

Re: 1993 Force 70 Not Charging

Sorry I missed your questions: It seems I have 3 sets of coils on my stator, 1 set going to my rectifier, and the other 2 going to my switch box. The voltage at my switch box is the correct according to the manual, but the voltage going to my rectifier is lower than what it should be only reading about 7 volts ac.