Steve G
Member
I thought I might share some info from my recent experience re-powering a CC 2185, as it might be of use to someone down the road.
The original engine was a Kohler CH18S-62588. I contacted Kohler tech support, and they replied with a list of compatible model and spec engines for the 2185. I'll attach an image. Basically, of a handful of compatible Kohler engines, the only one active (still in production) as of the fall of 2023 is a CH640-3126, intended for a Simplicity mower. After months of searching (Kohler engines in general have been hard to find for a year or more) I finally found one, purchased and installed it. Here are a few things to note for anyone considering the same course of action:
Same dimensions in all respects as the CH18S, but with 20.5 versus 18 HP. They share a service manual. Shaft length and diameter same as the CH18S. Engine footprint, clearances and mounting holes all the same. Has a vacuum driven fuel pump rather than the mechanical, for what its worth.
Throttle and choke linkage connections the same. Linkage plate a bit different, and I ended up affixing the throttle cable on the bottom rather than the top (or maybe it was the choke cable) to keep them from interfering with one another. Easy, at any rate.
Exhaust manifold lines up perfectly.
Flywheel has proper hole spacing, size and thread to accept the 2185 shaft adapter, with same setback as on the CH18 so it fits up tightly against the shaft. Easy swap.
The CH640 I received came without a grass screen, which affixes to the flywheel fan on the CH640 via four screws rather than seven snap points on the CH18S. I never did identify a grass specified for the CH640, but found that the 24 162 36-S low profile grass screen with hole fits perfectly. Essentially identical to the CH18S screen save for the way it mounts. Takes metric screws, #7 as I recall.
The cowls over the exhaust manifold on the front of the CH18S (at dipstick and linkage) could not re fully re-attached to the CH640. Not a big deal, and an easy mod to bend them a bit, add a couple of screws and get them close to where they were before. I had to mount the linkage-side one to the cowl that extends off the muffler. Pretty simple stuff anyway.
Wiring was straightforward. The CH18S had a male wire-bundle connector and the CH640 a female. I just recycled the connector from the old engine, wiring it onto the Cub side, and plugging them in.
Everything is working great. Only exception is my headlights no longer work. Not sure how to wire those back in yet, maybe something I missed or I'll need to modify, as the CH640-3126 is actually spec'ed for a Simplicity mower, not a CC. The need for a mod there is no surprise and a minor thing I'll figure out along the way.
Bottom line, having never done an engine swap before I was apprehensive going in, but it could hardly have been easier swapping out the CH18S-62588 for a new CH640-3126.
The original engine was a Kohler CH18S-62588. I contacted Kohler tech support, and they replied with a list of compatible model and spec engines for the 2185. I'll attach an image. Basically, of a handful of compatible Kohler engines, the only one active (still in production) as of the fall of 2023 is a CH640-3126, intended for a Simplicity mower. After months of searching (Kohler engines in general have been hard to find for a year or more) I finally found one, purchased and installed it. Here are a few things to note for anyone considering the same course of action:
Same dimensions in all respects as the CH18S, but with 20.5 versus 18 HP. They share a service manual. Shaft length and diameter same as the CH18S. Engine footprint, clearances and mounting holes all the same. Has a vacuum driven fuel pump rather than the mechanical, for what its worth.
Throttle and choke linkage connections the same. Linkage plate a bit different, and I ended up affixing the throttle cable on the bottom rather than the top (or maybe it was the choke cable) to keep them from interfering with one another. Easy, at any rate.
Exhaust manifold lines up perfectly.
Flywheel has proper hole spacing, size and thread to accept the 2185 shaft adapter, with same setback as on the CH18 so it fits up tightly against the shaft. Easy swap.
The CH640 I received came without a grass screen, which affixes to the flywheel fan on the CH640 via four screws rather than seven snap points on the CH18S. I never did identify a grass specified for the CH640, but found that the 24 162 36-S low profile grass screen with hole fits perfectly. Essentially identical to the CH18S screen save for the way it mounts. Takes metric screws, #7 as I recall.
The cowls over the exhaust manifold on the front of the CH18S (at dipstick and linkage) could not re fully re-attached to the CH640. Not a big deal, and an easy mod to bend them a bit, add a couple of screws and get them close to where they were before. I had to mount the linkage-side one to the cowl that extends off the muffler. Pretty simple stuff anyway.
Wiring was straightforward. The CH18S had a male wire-bundle connector and the CH640 a female. I just recycled the connector from the old engine, wiring it onto the Cub side, and plugging them in.
Everything is working great. Only exception is my headlights no longer work. Not sure how to wire those back in yet, maybe something I missed or I'll need to modify, as the CH640-3126 is actually spec'ed for a Simplicity mower, not a CC. The need for a mod there is no surprise and a minor thing I'll figure out along the way.
Bottom line, having never done an engine swap before I was apprehensive going in, but it could hardly have been easier swapping out the CH18S-62588 for a new CH640-3126.
