1541 / 1872 same engine?

[tinker3006]

Last year I bought my first ever Cub Cadet an 1872 that I didn't hear run until I drug it home and found out it had a bad governor after I cleaned the carb and got it running. Anyway about a month ago I bought a Cub 1541 that the seller told me it "wasn't getting spark, probably just needs a coil". So as I was looking for a coil online (Wow, they are pricey!) I saw a mention that the engines might be the same except for the carburetor, can that possibly be true? Can I simply pull the motor off the 1541 and install it in my 1872 using the carb and coil from the 1872 until I get it's original Kohler Magnum 18 rebuilt? And if I can use the 1541 engine are there any other parts (maybe a new fuel pump) that I ought to replace while I do the swap? Thanks for your time.

[dag1450]

From what i have read...Yes..Yes..and Yes! You got your work cut out for u just doing the swap. Maybe u should check the "coil" for yourself before getting too deep into the motor to reach the ignition. It might not b bad and just some other little switch or do-dad thing causing no spark. Keep us posted.
...and yes to the fuel pump too

[tinker3006]

Thanks for the reply Dag but why the quotes around the "coil"? I'd begun to think the engines were the same but still I am a bit stunned. The 1872 I bought is in really great condition other than the governor of course and the only reason I bought the 1541 was because I thought fixing the spark would be quick and easy and I'd mow with it until I got the 1872 engine either rebuilt or replaced and then resell the 1541. I guess I can quit looking for a reasonably priced Kohler Magnum 18 and just swap the engines I already have.

[dag1450]

Thats a good question Robert...I'm trying to figure this out myself. I'm not an electronic guy so I don't really know all the proper terms for all the different types of electrical systems. I guess I just wanted to call attention to the coil and let u know u will not b swapping a traditional round bolt on external coil......its a deep under the sheet metal magneto type coil. U aready knew this cause u were shopping for new ones.....idk. Maybe someone will come along and let u know some common issues w those tractors and no spark issue. I hear there r lots electrical connection and ground problems in the wiring harness
As far as your engines....almost sounds too good to b true don't it.

[JMotuzick]

I've done this swap,very easy! Yes, it will bolt right on. 6 boots for the frame/engine plate 2 for the rag joint and throttle/choke. You can change the whole manafold over if it's easier for you. As for the coil/no spark issue you can just swap from one engine to the next. Just be sure to set the proper air gap, I iust use old microfiche film. Works great, but getting hard to find these days! Also yo will need to change the muffler/exhaust tin work, or skip a front grill mesh. If you do that when u put the 1872 exhaust into the 1541 you won't be able to have any grill/hood/side Sheilds. Depending on how those last parts are you might be better off just parting out the 1541 and using the engine in the 1872.... I have a M18 here for parts too... Seams with no spark plugs the bore rusted up!

[Tom Scott]

My thoughts...

The 1541 is a nice machine itself. If your intent is to rebuild the 1872 engine anyway then I would start by just repairing the 1541 to use while rebuilding the M18 from the 1872.

Replacing the magneto in the Magnum is an easy weekend job; remove the grill and hood, unbolt the motor plate from the tractor frame, disconnect all cables and wiring, place engine on nearby bench, remove tin at firewall end of engine, replace and gap magneto. Bolt back together and re-install. As dag mentioned, just take the time to diagnose the old magneto to make sure it is really bad. The Kohler engine manuals are very good and are available on their website, and the M18 manual has a magneto checking procedure. If you don't have spark, it is likely bad, but if the kill wire is grounding out somewhere that could cause no spark.

With the 1541 repaired you have a tractor to use and you can take your time rebuilding the 1872 engine.

If you do decide to cannibalize the 1541, then do make sure you transfer the correct tin for the muffler box from the 1872. It is just a crappy job to not take the time to transfer the correct sheet-metal. My 1872 came to me with a pigged up motor swap, no muffler box, and it had melted all the decals and headlight wiring. Generally it is always worth a little more time to do the job right.

By not cannibalizing the 1541 you will have two good tractors when you're done. I don't know if you currently have any others in the fleet, but it is always good to have at least two machines so you can take the time needed for repairs when one goes down. I don't know how I got by with just one tractor way back when!

[tinker3006]

Thanks to everyone for all the input. I'm still stunned about the engines being the same, I sure got lucky for a change. I think I will likely end up using the 1541 engine on the 1872 while I rebuild the 18 horse with the bad governor and just parting the 1541 out. I will be sure to use the correct engine tins and exhaust for the 1872 so I can keep that tractor looking and functioning as it should.

[SWilliams]

I'd try the 1541 first. The higher axle and better turning radius makes them a great mowing machine.