My first Wheel Horse is a C-120 Automatic

[Bar Nuthin 885]

On 11/2/2024 at 6:17 AM, Blasterdad said:

Have you thought about adapting your adapter?  

 

Adapter adapted!

Surprisingly, it way outperformed my zero-turn!

Been a long time since I've owned a conventional tractor - 3 POINT TURNS ARE VASTLY UNDERRATED!!!

 

  

Edited November 8, 2024 by Bar Nuthin
grammar

[ebinmaine 69,684]

Niiiiice looking lawn!

 

Also nice usage of ear PPE.  

 

[kpinnc 13,077]

22 hours ago, Bar Nuthin said:

3 POINT TURNS ARE VASTLY UNDERRATED!!!

Takes a minute to get used to them doesn’t it?  I can’t remember how many times I’ve smacked my leaf vacuum against my house. 
 

Vey nice setup you have there! 

[Bar Nuthin 885]

3 hours ago, kpinnc said:

I can’t remember how many times I’ve smacked my leaf vacuum against my house.

 

I've always ran it attached to a zero turn. You can build a lot of momentum when whipping around. My worst one was taking out a garden hose hydrant out by the garden. Had to rent a mini excavator to correct that boo-boo.  

 

 

THIS ONE!

Edited November 9, 2024 by Bar Nuthin
add photo

[Bar Nuthin 885]

When I increase throttle, my voltage climbs to 18 volts (before I shut it down).

I’m assuming it’s a bad rectifier but I thought I’d post here to make sure I’m not jumping to conclusions. Is there anything else I should be looking at? And, yes, I checked it with my multimeter rather than relying on the gauge. 

 

Edited November 15, 2024 by Bar Nuthin

[ebinmaine 69,684]

1 minute ago, Bar Nuthin said:

When I increase throttle, my voltage climbs to 18 volts (before I shut it down).

I’m assuming it’s a bad rectifier but I thought I’d post here to make sure I’m not jumping to conclusions. Is there anything else I should be looking at?

 

 

 

DEFINITELY want to check that with a voltmeter.

 

More than one aftermarket gauge has offered incorrect readings. 

You should be more like in the 13.5 to 14.5 Volt range

[pfrederi 18,157]

Run a jumper wire from the case of the rectifier to the battery - terminal  see if that reduces it also check the voltage with a good quality multimeter ...gauges in tractors are frequently inaccurate

[Bar Nuthin 885]

Idle

 

2800 rpm - 17.3 and climbing. 

 

Edited November 15, 2024 by Bar Nuthin

[Bar Nuthin 885]

26 minutes ago, pfrederi said:

Run a jumper wire from the case of the rectifier to the battery - terminal  see if that reduces it also check the voltage with a good quality multimeter ...gauges in tractors are frequently inaccurate

jumper wire had no effect. 

[Handy Don 13,047]

The guys have you on the right track.

Pretty sure your model of tractor uses a voltage regulator and not a rectifier. Actually, your readings would make sense if you had just a rectifier, but I digress.

The only remaining question given those readings and a well-grounded regulator is to confirm you have a good battery. Most auto parts stores and auto service places have the proper gadget and will test one (of course ready if it fails to sell you a new one on the spot ).

If the battery checks out, then it’s extremely likely your regulator is toast--they do fail. Running like this will ruin a battery. 

[Bar Nuthin 885]

34 minutes ago, Handy Don said:

The guys have you on the right track.

Pretty sure your model of tractor uses a voltage regulator and not a rectifier. Actually, your readings would make sense if you had just a rectifier, but I digress.

The only remaining question given those readings and a well-grounded regulator is to confirm you have a good battery. Most auto parts stores and auto service places have the proper gadget and will test one (of course ready if it fails to sell you a new one on the spot ).

If the battery checks out, then it’s extremely likely your regulator is toast--they do fail. Running like this will ruin a battery. 

Battery is good. ‘76 C-120 doesn’t have a “regulator”. My understanding is that the rectifier acts as a regulator. 

[Bar Nuthin 885]

Just saw this on another post. I'll run a couple more checks after Tyson crushes Whatsizname!

 

[WHX?? 49,890]

I put that same cheapy flea bay voltmeter on a B-80 and it always read high compared to a DMM. I just recalibrated my eye ball and lived with it. 

Betting you got a bad reg. tho. 

[Handy Don 13,047]

15 hours ago, Bar Nuthin said:

rectifier acts as a regulator. 

Common interchanging of the two words that describe two different electrical components.

A rectifier converts AC to DC. Voltage in is voltage out. They are unregulated. They do not generate noticeable heat.

A regulator (e.g. the solid state ones used in WH tractors since the 70’s) both converts AC to DC and constrains input voltages from 14-40 to output voltage of 14-15 volts. It is the regulating feature needing to dissipate the “surplus” voltage/current that causes the device to heat up and hence the reason for the cooling fins.

 

Many small engines do have only a rectifier; some have only a single diode. They can do this because their stator for generating battery-charging electricity is specifically designed to deliver only 2-3 amps at about 12-15 volts when turning at 3600 RPM. Enough to charge a battery but not to cook it.

Edited November 16, 2024 by Handy Don

[Bar Nuthin 885]

53 minutes ago, Handy Don said:

Common interchanging of the two words that describe two different electrical components.

A rectifier converts AC to DC. Voltage in is voltage out. They are unregulated.

 

I appreciate everyone who chips in to help others in need here on Red Square. But what you're saying seems contrary to the Service Manual for my engine.

[Handy Don 13,047]

Confirms the dual function. Rectifier AND Regulator in one component.

While your regulator is not working properly @17+ volts output, it is still working partially. Using your DVM, measure the AC voltage at the two AC contacts of the regulator with the engine running at 3600. I strongly suspect you’ll see a voltage upwards of 30VAC, perhaps even 40VAC.

Edited November 16, 2024 by Handy Don

[kpinnc 13,077]

I would charge the battery externally and try the measurements again. I would also run it as is for maybe 15 minutes and see if the charge voltage begins to taper off. I would also try a different battery if you have one. 
 

A rectifier responds directly to the load placed on it. Simple Ohms law in action. Volts are equal to resistance times current. 
 

When you start your tractor, you dump a lot of stored energy at once. Directly after, your charging system has to work harder to bring it back to normal levels. It tapers off as the battery is replenished. Point being, you’ll see higher voltages until the battery is charged. Another possibility is your battery is getting old and places a greater load on the charging system. 
 

Several of my tractors charge as high as 16vdc or more immediately after starting, but this tapers down to 13vdc after a few minutes of running. A worn out battery or one with a bad cell can work your charging system excessively. 

Edited November 16, 2024 by kpinnc

[Bar Nuthin 885]

6 hours ago, kpinnc said:

Several of my tractors charge as high as 16vdc or more immediately after starting, but this tapers down to 13vdc after a few minutes of running. A worn out battery or one with a bad cell can work your charging system excessively. 

My battery tests strong, even under heavy load.

 

I disconnected the B+ terminal and check the output voltage at 3200 rpm. It varies between 17.5 and 18 volts.

I left it disconnected and used the tractor to vac leaves for just shy of 2 hours. Tractor ran great and when I finished the battery was still holding strong at 12.77 volts.

I'm wondering if voltage could have contributed to my first coil failing. And perhaps my original ammeter as well.

 

Right now, as it sits, I have a fresh internal resistor coil, points, condenser, RH10C plug and plug wire. The carb is clean and adjusted (maybe actually be tick rich now).

Since it runs great with the charging wire disconnected and the regulator test fails (per the service manual) I think I'll go ahead and replace the rectifier to make it a clean sweep.

Edited November 16, 2024 by Bar Nuthin

[kpinnc 13,077]

8 minutes ago, Bar Nuthin said:

Right now, as it sits, I have a fresh internal resistor coil, points, condenser, RH10C plug and plug wire. The carb is clean and adjusted (maybe actually be tick rich now).

Since it runs great with the charging wire disconnected and the regulator test fails (per the service manual) I think I'll go ahead and replace the rectifier to make it a clean sweep.

 

Sounds like a good plan. If nothing else, it removes one more possible faulty component. No more guessing on this. 

[Handy Don 13,047]

37 minutes ago, kpinnc said:

Sounds like a good plan. If nothing else, it removes one more possible faulty component. No more guessing on this. 

And I agree, over-voltage can affect other components beyond the battery.

[Bar Nuthin 885]

Santa paid me an early visit! 

 

[kpinnc 13,077]

On 11/15/2024 at 3:55 PM, Bar Nuthin said:

When I increase throttle, my voltage climbs to 18 volts (before I shut it down).

Looks like the gauge tops at 16vdc. I would say for several minutes after a start, it’s not terrible. 30 minutes of run time should have you back down around 13vdc. 
 

Cranking dumps a large amount of capacity from such a small battery. Multiple start attempts compounds this. That places a load on your charging system, and it responds appropriately. But it should taper down after a few minutes. 
 

Also- unless that is a high end gauge, a volt or two off is sadly to be expected. 
 

As has been said, check voltage with a known good multimeter. Then you will know for sure. 
 

My 310-8 (314) charges at 17vdc if I have to try a couple times due to long periods between runs. Then it drops back to 13-ish after and stays there. 

Edited December 14, 2024 by kpinnc

[Bar Nuthin 885]

@kpinnc - Thanks, but the new rectifier resolved my issue. My voltage meter was remaining pegged the whole time the tractor was running. When I disconnected the rectifier and tested it, the B+ terminal was reading between 17.5 and 18.5.

 

Since replacing the rectifier, the output of the rectifier read 14.5 on the multimeter and the gauge shows a steady 14v after a few seconds of running.

 

Someone suggested that I may have remedied a poor ground when I change it out - but either way everything is functioning well at the moment. When I got the tractor, the wiring was all wrong, The PO said the battery needed charged occasionally (but the B+ wire wasn't hooked up) it had the wrong coil, and the points would be fried after about 5 hours of running. From all of the mice nests it had, I'm guessing he picked it out of a barn then decided to flip it rather than fix it.

 

This horse has been ridden hard, but I think it's going to be a good one. The hydro seems pretty strong, (though, now I'm battling a leaking seal around the hydro input shaft). I haven't pressure tested it yet, but it pushes my trailer around well and handles my leaf vacuum like it's not even back there.

 

When I had the cylinder head off, I found it had a .20 over piston, no knocks, no smoke - and all the parts are there . The original carburetor needle was bent at the tip, so I put a $20 Wuhan carb on until I come across a needle at a reasonable price.  I'm hoping whoever rebuilt it had the good sense to remove the balance gears. Time will tell.

Edited December 15, 2024 by Bar Nuthin

[kpinnc 13,077]

11 minutes ago, Bar Nuthin said:

Since replacing the rectifier, the output of the rectifier read 14.5 on the multimeter and the gauge shows a steady 14v after a few seconds of running.

 

Someone suggested that I may have remedied a poor ground when I change it out - but either way everything is functioning well at the moment.

I’m glad you found it. It’s always nice to have your machine run as it should. 
 

Electrical stuff can be a bit tricky on these older machines. Even though mine are not “original”, I typically rewire everything just to be certain my connections are all good. I’ve even been known to make up my own harness here and there. 

 

And yeah, you can now test the old rectifier and see what you get- but your tractor is serviceable regardless. 

[Bar Nuthin 885]

1 minute ago, kpinnc said:

I’ve even been known to make up my own harness here and there

My wires are all kind of free agents at the moment - just to get everything working properly. At some point the whole tractor will get torn down for a facelift and I'll come up with a more organized wiring plan.

 

I plan to add at least one 2-prong connector for accessories like my weed sprayer, battery tender, and maybe an amber beacon light. I did this on my zero-turn and love it.

Runs through a lighted toggle switch near my controls.