Re-engine project Toro Wheehorse 268H, V-Twin Kohler to Briggs

92saturnsl2 · Feb 12, 2025

meep said:
This might get you close. I typed in “6 pin molex” and found this:

https://a.co/d/4OubEpv

I'll be darned if that didn't fit it perfectly. The $6 Chinesium connector (it came in a pack of 3 for that price!) doesn't look nearly as durable of plastic / metal pins as the OEM briggs that mates with it; I'll have to keep an eye out for hot/yellowing plastic on that end but at least I know which connector fits.

I'm pretty close to the finish line. Engine is bolted down securely w/ grounds attached, wiring harness looks factory fresh without modifying the new Briggs harness at all. PTO/hydro pulley mated up just fine like the old. Exhaust is done and solid.

Trying to think of what's left-- I have a place for the new starter solenoid, just need to fasten it and connect the wires. Engine came with a simple plug for oil drain that would make a *terrible* mess if used that way. I need to plumb a piece of iron pipe to it w/ a 90 degree elbow & cap (for future oil changes) before I fill it w/ oil, which is how the old Kohler was configured.

Throttle cable is a mixed bag. I can make it fully functional right away using the choke lever on the mower. It extends the Briggs throttle fully and even engages the choke at the end of travel (Briggs has a single unit tied together). The actual mower throttle cable is too short, it would wrap it against an exhaust tube to reach that area. Ultimately I plan on separating the functions, but I need to buy a longer throttle cable.

92saturnsl2 · Feb 15, 2025

Fired up engine for the first time. Engine would not start for the life of me on the initial try. Verified fuel as best I could (wet plug), spark, compression.

However, a shot of starting fluid into the intake got it going immediately. Engine will run all day long-- I tested throttle, PTO, charging voltage & all the various mower functions and it runs just like it did before. But anytime it's shut off, it will not restart unless you add a touch of starting fluid.

What I figured out after some troubleshooting is that when the keyswitch is turned to START, it is disengaging the fuel solenoid at the carburetor. In the run position the solenoid engages (audible click) but as soon as you turn to start, the solenoid disengages. I've verified this with a meter.

The electrical diagram shows the blue start wire connected to the violet wire via a diode before it reaches the fuel solenoid. This must have taken place at the old engine before I ripped things apart is the only thing I can figure. According to the diagram, the violet wire should be providing power to the fuel solenoid in all keyswitch positions except OFF. I'm scratching my head why the fuel solenoid is disengaged when turned to start as the only thing interrupting the violet wire is a 25A fuse.

92saturnsl2 · Feb 16, 2025

I consider this a finished project (except hood install). My initial wiring was wrong and missing a couple key diodes which caused the engine not to start and had the side effect of disabling some safety features. Everything works as it should now. Hoping all the white around here turns to green soon so I can put it to work.

92saturnsl2 · Feb 27, 2025

There was no way the mower hood would clear that long/tall snout that the "commercial" Briggs engine has-- aka cyclonic air filter. I anticipated that going in.

I could have avoided that by going with the "residential" engine which has a flat air filter cover and no oil cooler but I took my chances. Had to modify the hood some via a $25 Amazon hood scoop. The wife is going to work her magic- color match it, fill any gaps and make it look like it was part of the original hood.

The cyclonic air filter has an "exhaust" port, I felt it necessary to cut out part of the lens of the headlights (which I've never used and removed). I don't particularly care about looks but some day I'll find something to cover the hole that will allow air out.