Is this normal?

[Stepney 2,352]

Okay, so it's not a Wheel Horse, but it has a K-301 and Generator. I have a Cub Cadet 125, and whenever I start it, the ammeter needle flips back and fourth, (Compression release isn't much good...) And once firing, even at idle, the needle pins on the Charge side, for about ten or twenty seconds, then pops back to normal position (Charging) Then levels out when at full charge. My older Cub had no gauge, (A 102 model), so I have no idea if it did that, and my only GEN  Wheel Horse was a 702, and it's generator never worked. Is this a normal thing on a generator equipped tractor? I started to wonder if anything was different on this generator, (Being it has a ccw rotation, and a slightly different regulator.)

 

Well, anyway, Thanks in advance,

 

 

Spenser.

[gwest_ca-(File Mod) 11,393]

Don't know but here is the only Kohler manual I've seen with the starter/generator covered.

 

 

Garry

[wheeledhorseman 579]

A few bits of additional info would be useful.

 

I'm guessing you have an external starter motor and an alternator under the flywheel with external regulator somewhere with your K301. (y/n)

What is the full scale deflection on the ammeter scale  i.e number of amps?

Does it do exactly the same if you use a known good battery on the tractor?

 

After starting up it is normal to see a burst of charge being put back into the battery to replace the energy used to start it but unusual for this to read as full scale on the ammeter - hence my questions.

 

This would normally fall back to a small or no registered charge on the ammeter when the battery has been replenished.

 

The ammeter needle will 'flicker' on the negative (discharge) side as you try to start the  engine, this is due to the points opening and closing causing the coil to draw pulses of energy from the battery before the engine fires up and the charging system takes over.

 

[Edit] - re your comment about compression release, do I take it that the starter motor is struggling to turn it over as well? I know nothing about Cubs really but I think the 125 had a Sundstrand Auto transmission. From experience with my WH C-120 Auto, its imortant to disengage the drive to the hydr pump when starting the engine. If this isn't done the starter motor struggles (and draws a heavy load from the battery) as it is attempting to turn the hydro pump as well as the engine.

 

Hope this helps a little - I'll watch for your answers.

 

Andy

Edited July 16, 2013 by wheeledhorseman

[Stepney 2,352]

Yes, my Cub has an external Reg. And generator. (Starter Generator) This is a 1968 model. As for the gauge, I don't know. It's a vintage Cub style, with letters D- 0-and C... I know it's a 15 amp system, so I'm guessing it's a 15 amp meter, maybe tomorow I'll try a 20 amp gauge. Different batteries change nothing when starting and charging. Yes, the needle does return within minutes on the gauge.  

That's another oddity I see about this tractor, all the WH tractors I know of had a hydro-release lever, which made the engine easier to turn, but this is a shaft drive Cub, and it is Hydro, but the only release is a side mounted tow-valve. I had another Cub a few years back, which was a 3 speed, and it turned slowly too. I guess it's just a normal thing. The compression release is indeed working, I thought it wasn't for awhile. Changed the chunky old oil today, it's worked fine all day today. 

 

 

Spenser.

[wheeledhorseman 579]

Spencer, I suspect your charging system is working fine as doing a bit of research I came across this on another forum.

 

"If its an IH stewart warner meter it should go way up after startup" Only other Cadet owners on RS would be able to confirm. My guess would be that it's possibly a 10 - 0 - 10 amp scale hence with the Kohler 15 amp alternator it produces the full scale deflection after start up. I think I'd be happy with it as is.

 

Re the transmission arrangement it's obviously part of the IH design that the engine is permanently coupled to the hydro pump. My experience with my WH C-120 auto in winter if I forget to disengage the drive is that the starter motor struggles to turn both when very cold. Good luck.

 

Hope this helps a little.

 

Andy

[Jeff-C175 7,206]

It would be possible to add a wire wound resistor in parallel with the gauge to change the scaling.

 

An ammeter is really a voltmeter, a very low value one, maybe 50 millivolts full scale.

 

Inside the ammeter is a 'shunt resistor' that develops a voltage across it when current passes through it.  This internal resistor is a VERY low resistance.  Adding an external resistor in parallel will lower the internal resistance even lower and the gauge won't deflect as far.

 

The meter movement itself measures this small voltage and displays it as Amps.

 

Problem is that finding very low value resistors suitable for the purpose is sorta difficult.

 

Example:  If the actual meter movement is in fact a 50 millivolt part, a 10 AMP meter would have a 0.005 ohm resistor inside.  Even the very best multimeters have trouble measuring to this low value accurately.  The test leads themselves often have more resistance than that.

 

If you feel like fooling around and own a decent multimeter, you can connect it directly to the terminals on the ammeter and see the voltage across the meter.

Edited July 17, 2013 by Jeffpicks