Engine swap Kohler courage to Briggs intek

Yeah I know, swapping one POS for another, neither engine wins many awards.
But if it gets this machine mobile again under it's own power, so be it.
Machine is a Husqvarna 21K46.
Courage is knocking and smoking.
Both are single cylinder engines.
Pretty straightforward? Or will there be pitfalls? I would have liked to have put an opposed twin on that I have instead but am less sure that will fit this chassis without any modifications to the hood or side covers, so I picked up the intek.

The wiring harness probably wont mate up. Most important is are the shaft sizes the same OD and length?

I am assuming you are going from a single cylinder Kohler to a single cylinder Briggs.

I've done lots of swaps from the Kohler Courage single cylinder to a Single cylinder Briggs. If the Briggs has the correct diameter and length crankshaft, it is a drop-in replacement.

If both engines have the 6-pin electrical connector, the electrical is probably just a plug-in. At least it was on the new Briggs engines. The biggest issue is the muffler. If the Briggs has the side mount muffler, just put a baffle on it and turn it down. If you are worried about the paint and plastic trim, there is a MTD exhaust pipe that works perfectly with the Briggs engine and the Husqvarna muffler that mounts in front of the axle.

If you are going from Kohler twin to Briggs twin, the engine height sometimes comes into play. I've done one of those too. Sometimes, depending on which Briggs engine, you can't close the hood on the Briggs engine without removing the air duct in the hood. Then the engine overheats. (But it runs fine without the hood.)

At this point I'm more worried about the wiring situation and the bolt pattern holding the engine to the frame. The intek still has its pulley stack from whatever the donor was.
I got the donor intek from a garage sale as a combo deal along with a swisher tow behind that had a blown rod. I have a more suitable engine in the shed for the swisher already.
I know that has nothin to do with me putting the intek on this mower, just conversation there.
The intek is a sticker engineered 17-1/2 hp, which should be plenty for that machine.
Even though the original Courage was a sticker engineered 21hp.
When I went to move this mower out of the barn where I had it stored to bring it home for the transplant, I was surprised at how light it was to grab the back of the fender pan/ and pick up the whole back of the machine by myself. Relatively nothing to this Husqvarna.
I can't do that with my cub 129 or my ariens GTs.....

(quoted from post at 17:47:52 10/26/21) Yeah I know, swapping one POS for another, neither engine wins many awards.
But if it gets this machine mobile again under it's own power, so be it.
Machine is a Husqvarna 21K46.
Courage is knocking and smoking.
Both are single cylinder engines.
Pretty straightforward? Or will there be pitfalls? I would have liked to have put an opposed twin on that I have instead but am less sure that will fit this chassis without any modifications to the hood or side covers, so I picked up the intek.

Click to expand...

ounds like a darn good swap to me. I like the intek's.

both are single cylinder. Check.
Shaft size is identical. Check.
Exhaust isn't gonna be a problem. I can almost use the Husq/Kohler muffler, but it is on a slightly offset mount, and dropped down slightly. Id have to slightly heat and bend the exhaust pipe on the Briggs, if I use the muffler that came with the tractor. If I use the one that came with the Briggs, all I will have to do is drill 2, 1/4 holes on the mower frame near the 2 holes the original muffler from the tractor went to, and bolt it on. Easy. Bolts on the muffler that came w. the Briggs, are just tighter together (closer span between them, than the original muffler from the tractor). No problem there.

The Briggs block, bolted right to same holes Kohler was bolted to. No new holes needed there. Pulley stack went right back on the Briggs, easily enough.
Other than the wiring, the only difference is that I will have to run the Briggs' separate choke cable somewhere to the dash, and drill a hole for it to pop thru. The Kohler ran a single throttle/choke combo. Also easy enough. I got the choke cable with the engine. This engine bolted in, in place of the dud, way too easily..... I'm waiting for whatever is gonna trip me up making this swap..... (it almost always happens)

That leaves just the wiring as the mystery. I have the whole harness from whatever machine the Briggs came from. If I can figure out which wires to pair together, I think I will use the plug from the Kohler engine and cut the 2, flat white 2-wire connectors from the harness that came with the Briggs, and solder them to the pigtail I cut off the Kohler and plug it into the tractor and hopefully be good to go.

Then just to hope I didn't get duped buying this Briggs, and it winds up as a turd. I need to get it wired up to see....

Besides powering up the starter direct (easy, done that part too many times before to count) and putting 12V to the white wire from the carb solenoid to keep it open, I should at least be able to start the Briggs and make sure it runs before I go any farther, right? I have been messing with small engines since I was 12 (now 54) but have never yet had to mess with a carb solenoid (I deal with older machines that don't have such silliness) I'd rather hear the engine run before I go trying to figure out the conversion between the tractor and the new engine.

The tractor, and its original Kohler engine, have a 6 pin plug. Only 4 positions are used. 5 wires go to the tractor side of the plug, but 1 wire from the tractor side goes to a dead hole, on the engine side of the 6 pin plug/ and 2 of the wires (a blue and an orange) at the engine side of the 6 pin plug on the Kohler, both got put to the middle terminal on the Kohler's voltage regulator. (a blue and an orange, one stacked above the other, in the 6 pin plug)

The Briggs has 2, 2 pin plugs. One with a red and black (I think the red has the diode in it, black is AC for lights) These both definitely come from the stator. Then, the other plug has a black and a white. The white goes to the stupid azz solenoid on the carb. There was a red coming off the equivalent solenoid on the Kohler. I think the black in this pair off the briggs engine side, is the magneto kill wire.
can anyone enlighten me on which wires to tie together?

Drops right in. 10 mounting circle fits, electrical connections hook up, pulley fits right on the BS shaft with proper alignment. Only problem is choke and throttle linkage...out front rather than on the side....need longer cables. I bought a set on ebay for aboiut 25 bucks that mounts on the side of the cowling since I couldn't find a drop in to fit my Husqvarna. I like it better. Found the muffler used on ebay too. Mufflers are ok used....tough as nails. Have about 600 hrs now on the replacement....going strong. Actually I bought 2 engines off ebay....that 20 Intek and an 18 Intek V twin for my JD L110 which was a single 17.5 hp. Same thing...no problem.

Didn't mention both engines are swapping out single cylinder for V twins....whole lot smoother and faster starting, great power. The Courage soured me on Kohler engines for a long time......a real piece of crap....never had an engine vibrate so bad that it cracked the engine casting!!!!! This Jan. I bought a new Craftsman 46 with the 7000 series 22hp Kohler. They have redeemed themselves. They went out of their way to design/build a great engine.....well sorta. I got it for $1200 because it was sold and returned with 6 hours on it for not running right...seems the store repair folks couldn't fix it. I went through it and found that the sealer between the intake manifold and the crankcase wasn't applied correctly and it was sucking air. Sealed it properly and happy camper.

Its in, it starts easy and runs (after I replaced the old fouled out spark plug) but man this INTEK smokes like oil smoke BAD especially on initial startup when cold. It ain't fuel smoke.... it smells like oil and is blue. when I cut throttle in half it'll sit there and smoke like an old steam locomotive. when I very first started this engine it didnt seem that bad, I started it with the original muffler to the tractor. I had to use the muffler that came with the engine though. Originally I thought 3 years of storage plus sometimes being knocked over during that time may have filled the muffler with oil.... when I first started it with its original muffler I'm surprised I didn't get the fire Dept called on me, it smoked heavy for ~1/2 hour straight, before it cleared up, I couldn't even see across the road thru the smoke, at that point.... after that initial 1/2 hour it cleared up immensely, now just smokes mostly on startup. It runs too good, for it to seem like there is too much wrong with this engine.
That said I am not that familiar with the INTEK series, other than the bad rap I see it get on the forums. could it be possible to have something like a dislodged valve guide letting all that oil pass thru when the engine sits/not running????
My thoughts are to put the deck on and run it a while and see what happens..... I hope not to have to source a different replacement engine, for this machine. that would make it border on not worth it....
as I had planned on this machine as a flip.