I have an almost 10 year old Craftsman 917.270930 tractor with a Briggs 461707-0145-E3 20 HP I/C (Industrial/Commercial) engine and 42" deck. It's given good service in the several places we've lived during that time. In the last few years, I've replaced several things, most recently the deck spindles (one had the pulley strip out), belts, deck pulleys, and the magneto (? term) assembly with plug wires. This engine has no external oil filter.
The tractor started running rough & losing power intermittently, so I started doing some research into replacing it. I looked at several brands as well as the newer Craftsman tractors. I thought I had found a good deal on a ZTR with a 26 HP Briggs & 50" deck reconditioned for $1899 (carries the same warranty as new), but the local Sears is terrible for sales- long story, but after a couple of weeks, they "couldn't sell it to me" and the manager was always in a meeting and never called back. I found a tractor they could
sell with a 24 HP motor & 42" deck for $1299 plus tax, so I was looking at about $1400.
Since my deck was in real good condition and the repair was only $80 for all the parts (I do all my own labor), I looked into getting a new engine versus a new tractor. I did a lot of reading here before joining, and then shopped.
First, a word about engines and me. My wife & I like the commercial where the couple is shopping for a TV and the man says "If we don't go bigger now we'll regret it later", then a few seconds later they are in the jewelry department and the woman says the same thing to him. I have four foreign cars that I have installed Chevy V8 motors into, so the idea of "going bigger" is one I like. I noted the newer tractors for the most part had more powerful engines, so I figured if I was replacing a 20 HP, I should "go bigger". While I was at it, I was going to add an oil cooler and some gauges- combo hour meter/tach, and a triple gauge panel consisting of oil pressure, oil temperature, and volts.
I found my B&S motor had a 1" shaft with a 3.15625" length (3 & 5/32"). I narrowed my search to engines available with this shaft sizing.
I did market research and the best value I found was a Kohler Courage twin cylinder 25 HP, model SV730-002 that I got on ebay for $499 shipped.
Right now I am still in the planning stage, and have completed a wiring diagram for the conversion using the factory diagram from my owner's manual (I noted Sears no longer has this info in later models, at least the ones with the SV730 Kohler did not) as well as one from a Kohler service manual I downloaded. I'll link the files since most are too large to attach or post as a picture.
Craftsman 917.270930 wiring diagram
(I colored a few wires to make them easier to see)
Kohler SV730 wiring diagram
Picture of backside of Kohler ignition switch
(I found this picture online, I'm using my old switch)
Combined wiring diagram
I looked quite a bit for wiring info, so I wanted to be sure I posted it here for the next guy to use.
In summary, the main difference I found was the B&S used AC to power the headlights and Kohler uses DC. I checked the bulbs on my tractor, and they are 12V automotive #1156, usually used as a back-up light bulb in older cars, so 12V DV would work fine for them. The Craftsman ignition switch controls the lights, so it was just a mater of re-wiring the feed so that terminal (A2) gets 12 volts.
For the oil cooler, I found the Kohler kit was over $100. The filter thread size is 3/4-16, and the OD of the filter gasket is around 2.75". I found a Jegs' brand #51712
thermostatic sandwich adapter in this size from Jegs on ebay for $26 shipped (it was cheaper to buy it there than their website due to lower shipping).
For a cooler, all automotive ones were too big. I found a power steering cooler
with 90 degree fittings and a mounting bracket on it on ebay for about $16 shipped. I'm planning to attach it on top of the shroud so air will be drawn through it when the engine is running.
I'm planning on plumbing in the adapters for the gauges at the sandwich adapter since it has 3/8 pipe threads for the input/output. Unlike the wiring, I need to have the parts in hand to figure that one out.
For the gauges, I wanted an hour meter to replace the ammeter in the left side of the dash. I found the opening was about 2.25" W x 1.3" H. The cheapy combo units sold on ebay were too small. After doing some searching, I found the Autonnic
unit that is around $56 shipped. It has several mounting options, and I chose the cam lock style since the unit is around 2.125" W x 1.44" H. I figure I can grind/file the opening to make it fit OK. They offer several mounting options.
Here is their stock image of the product:
Next up were the trio gauges. I wanted the mini (1.5") size. Sunpro makes a couple versions, as does Equus. I settled on the Sunpro #CP8090 that I got for $32 shipped on ebay. They consist of mechanical oil temperature & pressure gauges and a voltmeter. I plan on mounting them in front of the hood opening on top of the dash. Summit made a slick setup for this with enclosed electric gauges, but it was $80 plus shipping.
When I totaled up what I bought, I found I had saved about $650 over the cost of the $1299 tractor, which of course does not have any of the gauges or the oil cooler.
I'm hoping to get all of this stuff here by next week, so I can get underway with the upgrade. I will update here as I make progress.