1978 Cadet 1650 Not Charging

[ollie2009]

My trusty old 1650 looks like it is not charging. Yesterday after cutting grass for about 30 minutes, the motor started to cut out. As soon as I turned off the electric clutch the motor limped back to life, and then ran as usual. Soon as i turned on the electric clutch again, same thing. Turned it back off and then went back to the garage. Shut it down, and went for lunch. After coming back, it would not start. Put the battery on the charger for a few hours, and when tried to start it after supper, started up great. After cutting grass for about 20 minutes or so, same thing. This time after shutting the clutch off and letting engine get back up to speed, when I turned the clutch back on, I noticed that the voltmeter registered a discharge. Turning off the clutch and voltmeter went to 12V (on the guage), but never charged any higher then that.
Can anyone give me some troubleshooting advice on how to find out why it's not charging. Would really appreciate any help you can offer.

 

[Bob_Bainbridge]

It's been awhile since I had my 1450 but if I remember correctly the alternator is under the flywheel. There is a rectifier assembly mounted on the lower part of the engine by 2 screws. This is most likely the failing part. You can check for AC voltage from the alternator going into it. You should be getting 13.5-14.5 VDC to the battery.

Bob B.

 

[The kid]

I found this posting here you might take a look at. He had the same problem. Cub 1650 not charging
I recently overhauled my charging circuit. What happened was the same symtoms as yours. What I found was a flywheel dropped a couple of magnets and destroyed the stater (alternator) and the stator took out the rectifier/regulator. I found a good used stator on eBay. The flywheel bought new from Kohler. Bought the recifier off ebay. Just a word of advice. If you have to replace the flywheel. Spend the extra buck and buy a new one. A used one might lose the magnets too. The new ones have improved bonding adhesive. -kid

 

[gladiater]

if you do not want to spend extra bucks on older unit, i have used jb weld and have successfully rebonded magnets to flywheel.on many unit's

 

[The kid]

if you do not want to spend extra bucks on older unit, i have used jb weld and have successfully rebonded magnets to flywheel.on many unit's

Yes sir, JB weld would probably fix it till one of the other magnets let go. Personally I wouldn't trust a flywheel that just destroyed my stator on another stator. It's well documented on the net that the older flywheels where prone to have magnets come loose. So where do you get replacement magnets, and how to do verify correct orientation so the field is not interrupted? -kid

 

[gladiater]

you will see the old glue spots on the wheel for proper orientation,buying a flywheel will solve the prob's fine, BUT some flywheel's are no longer avail,if you are buying a used one on ebay,might have the same prob

 

[The kid]

you will see the old glue spots on the wheel for proper orientation,buying a flywheel will solve the prob's fine, BUT some flywheel's are no longer avail,if you are buying a used one on ebay,might have the same prob

My 25 Hp Kohler is no longer made nor is the original flywheel. They sold me an upgraded version where I had to cut two small ears off the plastic shroud that covered it. Reattaching the magnets on mine was not an option. The magnet(s) came lose and destroyed the stator. The magnets where also destroyed. Chances of a magnet coming loose and surviving are probably slim to none. I have pictures of the mess if you doubt my word. Exact replacement may not be available. But one that will work I'm sure is. The only item I bought used was the stator. It was a 15 amp stator that was removed from a blown engine.

His problem of not charging if it's not the battery is probably a damaged stator like mine was. It is a very common problem with older engines. You should know that of all people here. Putting a bandaid on the problem is a poor recipe of a repair on equipment you intend to keep. If the OP wants to patch his pride and joy that is certainly an option. From the picture he provided I for one would want my vintage collectible repaired properly. The old saying. "You can pay me now, or pay me later" comes to mind when patching something of this nature. Then again I'm not in the patch repair business either. Your mileage may vary. -kid

 

[gladiater]

yes well said "pay me now or pay me later that's why i keep saying use the proper tranny fluid in the 2000,3000 series tractors, just quoting you...

 

[The kid]

yes well said "pay me now or pay me later that's why i keep saying use the proper tranny fluid in the 2000,3000 series tractors, just quoting you...

What? I was talking about a flywheel.. -kid

 

[ollie2009]

Tried replying before, but looks like it didn't go.
I am just now getting at my tractor, and would like some troubleshooting tips. To check the stator integrity, would I just do a continuity check across both wires coming from the stator? Can I check the rectifier with a multimeter? Or do I have to have it conected, the tractor running and just measure the voltage on the 3rd terminal on the rectifier to ground to see if I am getting voltage? Any tips you can offer would be greatly appreciated.
Thanks

 

[mark1]

Hey.check the plug that plugs into the regulator.there's a small regulator/rectifyer with a plastic plug and 2or 3 wires that plug into it.mine had a loose wire and got hot and no longer made good contact and of course stopped charging.when I fixed it all was well again.It's low on the side of the housing that's over the flywheel. let us know!

 

[ollie2009]

Just got back in from garage. Checked all wires and could not see anything apparent. Did a continuity check between the stator wires and good (very little resistance), actually did this through the plug at the rectifier(off the rectifier of course). Checked the resistance from the 3rd wire on the rectifier to the ign switch and good also. Any suggestions on how to verify the rectifier working with it removed from the tractor?

 

[The kid]

Just got back in from garage. Checked all wires and could not see anything apparent. Did a continuity check between the stator wires and good (very little resistance), actually did this through the plug at the rectifier(off the rectifier of course). Checked the resistance from the 3rd wire on the rectifier to the ign switch and good also. Any suggestions on how to verify the rectifier working with it removed from the tractor?

Clipped from member on smokestack.com.

Yes, You can bench test it with a Ohmmeter!

If it has three legs, two AC and one + as you indicate it would be a FULL WAVE rectifier! The + is POSitive DC output end of the rectifier!
Place ONE probe of the Meter (use the BLACK lead), (use RX1 scale) on the + and the RED probe to the AC terms, ONE at a time and compare the readings! They should read the same on the Ohms scale, either infinity (max) or both with same lower readings! Main thing is they both read the same as you leave the Black probe on the + term. Now reverse the probes (RED probe to pos+) and read as before, leaving the red probe on the + and the black to each AC term. The reading should be the same! When you reverse the red and black probes to take the readings if a or the readings stay low the or a diode is shorted! If the or A reading stays high their is a open! (their are two diodes in the epoxy with the diodes CATHODES+ tied together at the + terminal and each individual diode anode at the AC terminal! "

When reinstalling the rectifier. Make sure you secure the ground wire as it was. It won't work without the ground. I verified mine was bad with this procedure. To properly verify the stator the engine needs to be running to check for 28v AC across the AC terminals. The stator integrity could be damaged and the wire may not measure as open.

 

[ollie2009]

Hey Kid,
Back again from the garage, and just read your post. Thanks for the advice.
This afternoon I found a troubleshooting chart for my 1650 Cadet with a 15Amp stator circuit. For anyone else who may look at this thread here is the info it gives: 1). Remove connector from regulator (rectifier). Start and run engine at 3600 RPM, and measure the AC voltage across the stator wires. If the voltage is 28V or more the rectifier/regulator is faulty. If voltage is less then 28V problem probably in Stator. In my case I was gettin 32V, so Stator is Good, issue with the Rectifier.
2) you can check the Stator using an ohm meter with the engine NOT running. if the resistance is 0.1 / 0.2 ohms then the stator is OK. If resistance is infinity then stator is faulty. 3). Check resistance from each stator wire (one at at time) to ground. The resisitance should be infinity, if not the stator is shorted and is faulty.

Thanks to everyone who helped me out. Now I just have to find a supplier for an inexpensive unit. I'm from Canada, and here they want $76.00 then add anothe 13% for tax! Any one know of a good place to get one in the US (I live in Eastern Ontario on the Northern NY border)

 

[The kid]

Hey Kid,
Back again from the garage, and just read your post. Thanks for the advice.
This afternoon I found a troubleshooting chart for my 1650 Cadet with a 15Amp stator circuit. For anyone else who may look at this thread here is the info it gives: 1). Remove connector from regulator (rectifier). Start and run engine at 3600 RPM, and measure the AC voltage across the stator wires. If the voltage is 28V or more the rectifier/regulator is faulty. If voltage is less then 28V problem probably in Stator. In my case I was gettin 32V, so Stator is Good, issue with the Rectifier.
2) you can check the Stator using an ohm meter with the engine NOT running. if the resistance is 0.1 / 0.2 ohms then the stator is OK. If resistance is infinity then stator is faulty. 3). Check resistance from each stator wire (one at at time) to ground. The resisitance should be infinity, if not the stator is shorted and is faulty.

Thanks to everyone who helped me out. Now I just have to find a supplier for an inexpensive unit. I'm from Canada, and here they want $76.00 then add anothe 13% for tax! Any one know of a good place to get one in the US (I live in Eastern Ontario on the Northern NY border)

They are plentiful on ebay. Anywhere from $15 - $40. That's where I bought mine. Good luck and glad the repair won't be too pricy. -kid