Electrical Question

[JC 1965 1,530]

I replaced the engine on my C81 with an old K 301. It runs great but i noticed that the amp gauge was always on the negative side even with the engine at full throtle. I checked the ac voltage on the two ac wires coming from the stator and was only getting 3 or 4 volts. So i pulled the flywheel and sure enough the stator was fried. I replaced the stator and now I'm getting 37 volts ac.and the amp guage is running on the pos. side and as i rev up the engine the amp guage goes even higher. Can I asume that i have the problem solved ? I don't know to check the regulator but since it's charging don't that mean the regulator is working properly ?

[rmaynard 15,406]

Check the voltage at the battery when the engine is running. It should be about 14.5 volts DC.

[JC 1965 1,530]

Bob, When i check the voltage accross the battery terminals i get 13.9 volts DC

[Wheel-N-It 2,968]

I think it is safe to assume you are in good shape now.

[Save Old Iron 1,566]

Now you have to think about why the stator fried in the first place. Old age? Excessive engine vibration? Possibly a near dead battery demanding a constant diet of high amperage eventually overheating the coil?

Watch the ammeter. A battery in good condition will require only a short period of high amperage draw from the stator. The high positive indication should quickly TAPER OFF to a trickle within a few minutes.

If you have minimal electrical accessories in use (and your battery is in good condition), the ammeter should be back down to near zero charge rate after a few minutes.

[JC 1965 1,530]

Wow chuck !! your just the person I think can help me out. First i don't know why the stator was bad, probably bad when I got the engine. I know this new stator is working properly. Now I'm questioning the condition of the Regulator/Rectifier. I checked the B+ terminal on the RR with the 2 AC stator wires connected and the engine off with the key in the on position, I'm getting the same voltage as I get across the battery terminals 12.6.DC. I assume that is ok. ( Forgot to mention the battery is new} Now here is my problem, With the engine running at 3600 RPM and the 2 AC stator wires connected, when I check the B+ terminal on the RR I get 22 Volts DC. From everything I've read it should be around 14.5 volts DC. Is that correct ? I've never had RR problems before. I have been searching The forum for info. but a lot of what I've read is confussing. Hope you can help me out. Thanks !!

[rmaynard 15,406]

Check to be sure that the R/R is properly grounded. An bad ground can produce voltages that are too high.

[JC 1965 1,530]

Bob, I cleaned the back of the RR and the surface that it mounts to. I also used star washers on the back side of the mounting surface. Would it help to run a jumper wire from the RR cooling fins to the tractor frame to make sure it is grounded ?

[Save Old Iron 1,566]

A quick jumper between the battery (-) terminal and the regulator case will tell if the RR needs replacement. If B+ doesn't drop to 14(ish) VDC, replace the RR.

[rmaynard 15,406]

What Chuck said is what I would recommend as well. Just be sure to clean the oxidation from the aluminum fin of the R/R case where you connect the jumper.

[JC 1965 1,530]

Thanks Chuck and Bob, I will hook up the jumper tomorrow. I will let you know the results. Thanks again !! :thumbs2:

[JC 1965 1,530]

Chuck and Bob, Today I cleaned one of the fins on the regulator and hooked up a jumper wire from the Battery neg. post to the fin on the RR that I cleaned. I checked the B+ terminal and got 19.5 volts DC. So I guess I need a new RR. Thanks for your help !! :thumbs2:

[rmaynard 15,406]

You can get a R/R new from Milford Power for about $40.00.

http://www.milfordpower.com/R10297-Voltage-Regulator-Replaces-Kohler-41-403-06-p/r10297.htm

Good used ones can be found on eBay.

[JC 1965 1,530]

Boc , Thanks for the link to milford power. I'll check them out.