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ztnoo

Identifying The Correct Rectifier For A Kohler Engine?

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ztnoo

I have a 1969 GT 14, 1-7741, which originally had a K321 14 hp engine that gave up the ghost.
That was replaced with a K341 16 hp engine.
The original rectifier was used when the new K341 was installed and performed fine.


I am now in need of a new rectifier because of broken male spade.
How can I identify the proper rectifier to match with a Kohler engine (in my case for a K321 or a K341), and what resource can I research to obtain that information?

Regards,
Steve

 

 

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Aldon

I'm not an expert but I believe one of the electrical swami's will chime in hopefully.

 

I believe the Kseries were 15 am systems so a 15 amp rectifier with three tabs AC -, B+, and AC + is what you need.

 

I think if it has those three, it does not necessarily matter how they are configured. 

 

I went with with replacement that was new manufacture and 3 in a row rather than the configuration with the one stacked over the other two tabs for easier access when doing the re-wire. 

 

I hope an expert chimes in though and have "followed" this thread to get info myself.

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ztnoo

Aldon,

I know it makes no difference as to the arrangement of the three male spades on the rectifier. Those spades are always well marked and identified, so its almost impossible to get them mixed up as long as one can see. Stator wires to the AC spades, battery/ignition wire to the B+ spade.

I'm just thinking there has to be info out there somewhere either directly from Kohler or elsewhere that pairs up Kohler engines with their appropriate rectifiers. I'm looking for Kohler part numbers for appropriate rectifiers.

The one hint I have from the owners manual states the alternator is 10 amp (to go with the original K321), so I'm assuming that was the spec on the rectifier as well.

If my K341 alternator was in fact of larger amperage (which I don't know), it still seemed to function fine on what I assume was the original 10 amp? rectifier.

 

Steve

 

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oldredrider

It's been my understanding that the rectifier with the 3 straight posts is for a 10 amp stator. Original on the GT14.  The rectifier with the 1 over 2 post setup is a 15 amp model. 

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gwest_ca

Do you have the Kohler spec number for the K341 off the engine data decal or plate? That should lead us to the Kohler IPL that shows the stator used.

 

Garry

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ztnoo

Spec#  71179

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gwest_ca

Here is your parts list

https://www.partstree.com/parts/kohler-engines/engines-horizontal/k341-71179-kohler-k341-engine-k-series-service-engine-16hp-11-9kw-specs-71105-71384/

The 2nd ignition page shows the stator 237878-S as being 15/20 amp. Don't know how they get that but suspect it is the 15 amp as we know it and 20 amp if they stretch it like everything else.

There was never a 20 amp regulator but there was a 25 amp.

I'd go with the 15 amp.

 

Garry

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ztnoo

Thanks Garry!

YOU are THE RESEARCH WIZARD!

Amazing!

Regards,

Steve

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Aldon

I went with 15 amp regulator from Isavetractors.com

 

Aldon

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gwest_ca

This old Kohler service manual shows the wire positions for the regulators used.

 

This is the one you want

Kohler 4-72 SM Section 07.7-7.12 Altenator charging systems HR.pdf
7 pages 3.14MB

 

Notice the 15 amp can have 2 different locations for the DC+ terminal but will guess the body of the regulators are marked accordingly.

 

Garry

 

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ztnoo

Aldon,

Did this rectifier hole mount spacing fit the mounting holes in the OEM location (above left side drive disengagement pedal) on the inside left side body panel???

The weird thing is all the rectifiers I have looked at are ALL OVER THE MAP in pricing.......all the way from $12 to way over a C note. Its nuts. They all supposedly do exactly the same thing.....change AC to DC. Why the price differential?

Garry,

Super info!!!

Thanks,

Steve

 

thumbup.gif.a6726fb5ef5ab4d50d9cf5d2ee41

Edited by ztnoo

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Aldon

Steve,

 

I have not yet installed as motor needs repainted before I install and start wiring.

 

in the pic, there are 3 rectifiers. The two older ones came off 2 different GT14's. One which I'm restoring the other off my parts tractor. One is configured like the new one to the right with tabs all in a row. Other has two stacked and two on bottom row.

 

All 3 have same hole spacing for mounting. Although from left to right, they each get smaller than previous.

 

the red one on left is the stacked tab configuration but on of tabs is broken off. The middle one worked but as I am refreshing the tractor, I will install the new one on right and keep the middle as a spare.

image.thumb.jpeg.b55a6aa91ba299f52f9dbbc

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ztnoo

Aldon,

Great pics!

I haven't pulled mine off the tractor yet. That's on tomorrow's agenda before I get to ordering something.

My old rectifier (which I am assuming is a 10 amp unit), appears from what I can see, to be like your middle unit....three spades stacked one above the other (I like this layout too, although a one over two spade layout would perform exactly the same).

It has significant heat sink fins like yours, but not as massive as the rectifier on the left.....that thing is a real horse when it comes to surface area.

I think its hard to imagine how hot these babies can get...but they really do I guess...I've never touched or felt one after running for a hour. I'm going to put that on my list of things to test in the future, out of curiosity.

Interesting those two older units are stamped "REPCO", which I would assume was the original manufacturer.

Your new unit looks really nice and has lots of finning, although not spaced as widely as the other two. This one is on my very short list of choices, thanks to you.

Steve

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KC9KAS

image.jpeg.a686f4bc1529cb9dfd5d9f393e2a1

I recently bought 2 of the new ones (on the right in the photo) and neither one of them  worked. They were from EBay and did not put out enough voltage.

I ended up getting new ones from STENS.

I did get my $37 each back though.

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Aldon

KC9KAS,

 

I appreciate the heads up.

 

If mine is defective I will go Stens next as well.

 

unfortunately I wil likely not be able to get the reimbursement as it will be some time yet before I can test it.

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Wishin4a416

Not to hijack but since were on the subject, does physical size come into play at all. The reason is, the one on my C-160 is bigger than one I picked up on ebay for my current project. Both have the stacked tab configuration. The one on the top is the one that matches the bigger ones in the pictures above. On the bottom is the smaller one but with stacked tabs.

 

 

IMG_1893.JPG

IMG_2425.JPG

Edited by Wishin4a416
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ztnoo

Did you install and attempt to use each one and discovered at that time they didn't work, or did you find that out by bench testing them?

Your's were from eBay, and Aldon, yours was from iSaveTractors, right? Surely they would refund you if it doesn't work and you still have a receipt or invoice as proof of purchase.

 

KC9KAS, maybe you got a unlucky roll of the dice......maybe they were just part of a bad batch of parts. What was your seller's user name, if you recall? Any huge hassle with him or eBay to get refunded?

 

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pfrederi
16 minutes ago, Wishin4a416 said:

Not to hijack but since were on the subject, does physical size come into play at all. The reason is, the one on my C-160 is bigger than one I picked up on ebay for my current project. Both have the stacked tab configuration. The one on the top is the one that matches the bigger ones in the pictures above. On the bottom is the smaller one but with stacked tabs.

 

 

IMG_1893.JPG

IMG_2425.JPG

 

 

In this case i do not think size matters electrically.  Mounting wise???  Consider the rectifier used on Twins (KT and Magnum) are only abut an inch wide 2 inches long an 3/4" thick and they are 15 amp.  They rely on airflow under the blower housing for cooling  Buit I mounted one on my D200 under the hood stand and it has worked for a couple years/

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ztnoo

I'm actually somewhat surprised at their size in relation to the hp and electrical demands of the typical lawn tractor. They seem relatively large in most cases.....at least to run these older flat head engines.

Most have reasonably heavy castings for the body and considerable finning for sufficient air cooling, so that says something about how hot they must get. Anyone ever point an infrared heat sensing device at a rectifier while running or shortly after the engine has been shut off? I'd be interested to know the typical temperature operating range.

The sensitive electrical innards are covered with a resin or polymer of some sort to more or less waterproof the guts.

Observation leads me to one conclusion......if these have an Achilles heel.....its those thin, exposed, metal spades for the AC and battery hookups.

They stick out of the body of the rectifiers unprotected in most cases with these older tractor, and just seem to beg for something or someone to bend or break them off.

Given the extremes of heat/cooling cycles and high vibration these are exposed to, I imagine this is a very common failure....especially after 40-45 years of operation

The best way to minimize damage is to tuck them away from danger zones and places an operator doesn't usually come in contact with his tractor.

The following pic duplicates the positioning and location on my GT 14 and shows a well protected (what I believe to be) OEM location, but this is not my tractor.

rectifier.jpg.089b8b07bb580c64955067d37b 

 

This pic shows a much simpler and easier installation, but exposes the rectifier and its critical wiring outside the left side body panel, and makes is much more susceptible to damage.

56b7aa0e9612d_gt14_rectifieronoutside.th

 

I pulled my rectifier this afternoon to see what I really had in preparation for ordering a replacement. Note the half broken AC spade on the right.

56b7ab3fa4e8b_mine1.JPG.782ff6b3a03bf296

56b7ab86f0763_mine2.JPG.de48628b270315a4

 

After a bit of cleanup, it was revealed this is a REPCO unit, like Aldon's two examples.

56b7ac1ef0c73_mine4.JPG.b04669a64af268a7

 

A side shot reveals the following info:  5 74    AC B+ AC    FG4720-B (or possibly D)

The last character shows evidence of wear in its upper area and I think it was "B" originally.

The first characters 5 74 might be a month/year of manufacture, but if that's the case, this wouldn't be the original that came on the tractor.

It could denote unknown info unrelated to a date.

56b7ae083e24e_mine5.JPG.8b29c3504dc69a45

 

 

Edited by ztnoo
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gwest_ca

I've been mounting these so the terminals are pointing down. The business end of the regulator is closest to the terminals and heat rises. If the terminals are up 1/2 the heat sink will see very little heat.

Have one of those fancy thermometers so will check temps next time I'm out if I think of it.

 

Garry

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KC9KAS
8 hours ago, ztnoo said:

KC9KAS, maybe you got a unlucky roll of the dice......maybe they were just part of a bad batch of parts. What was your seller's user name, if you recall? Any huge hassle with him or eBay to get refunded?

DB Electrical, and it wasn't hard to send them back or get my money back. Easy to work with.

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ztnoo

KC9KAS, Thanks for giving us the seller source. Could you link us to your Stens source?

Aldon, since you bought yours from a different seller, maybe you'll be OK.

DB is in Kingsport, TN. iSaveTractors is in Hollis, Maine.

Both company's items could come from the same manufacturer, but with the way lots of things are sold and not clearly marked or identified anymore (particularly from China), you have an almost impossible time tracing the problem to the original source.

 

 

 

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ztnoo

OK, back to the rectifier dilemma.

Like Aldon, my preference was for a 15 amp, lineal 3 spade arrangement.

The only 15 amp rectifier like that I could locate anywhere was offered by iSaveTractors.com

I inquired of the company about this rectifier and here is the response I received form Norman Ng, who I presume is the owner or the company agent delegated customer email inquiries.

The reply:

"Thank you for contacting me. At this time I am actually sold out of the Regulator Rectifiers. I am expecting my next shipment from the manufacturers on March 3rd.

When I get them back in stock I would be happy to measure the mounting holes for you. We ship everything we have in stock same day via USPS Priority Mail. You will typically get everything within 2 to 3 days.

I work very hard to keep everything I have listed in stock and ready to ship. However January brought an unexpected increase in sales that have cause me to sell out of 3 items.

If you would like I can notify you when I receive more of the Reg/rectifiers in stock.

Please let me know if you have any other questions,

- Norman

 

  iSaveTractors.com

 

  Quality Aftermarket Parts for Kohler K Series Engines, and More!

 

  Find us on Facebook!

 

  http://www.facebook.com/isavetractors"

 

Well so much for that supplier....I'm not going to wait about three weeks and hope everything works out.

I need a 15 amp rectifier NOW!

Sorry, Norman. C'est la vie.

 

Here's what I chose off eBay from a seller by the user name of emsglobaldirect.

Still 15 amp, but with the 1 over 2 spade arrangement.

Looks great....beautiful in fact.

If it performs as good as it looks, I'm a happy camper and a rejoicing rectifier procurer.

 

IMG_0475.JPG.d69eb8fa2901cb1564c1cf376ca  IMG_0476.JPG.a61690e7fb72e321fabde9b1d2e

 

IMG_0480.JPG.e3aed69179e50a88bdeb7188262

 

I'm going to label the back of this unit with the amperage, in case I die tomorrow, the person that winds up with this after I'm gone will at least have a clue about the capacity of the rectifier.

Meanwhile. I'm off to other winter garage adventures with my GT 14 before Mother Nature requires my presence in the mowing regiment here at my Hoosier Abode.

 

Regards,

Steve

 

Edited by ztnoo
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