Questions on replacing a Kohler CH18S engine with same make and model but different spec.

[Steve G]

Hello to all.


Looks like I may have to re-power (or punt) my CC 2185. The engine is a Kohler CH18S spec 62588. If I can get hold of another CH18S, but it's a different spec, what problems am I likely to run into? Are the shaft placements, and intake and exhaust manifolds for example in the same places on the CH18S regardless of spec? Are the pre-drilled holes in the flywheel in the same place (so I can attach my shaft cup)? That would be critical. I figure if the PTO shaft diameter is different, but the same length, I would need to replace the PTO clutch, but no big deal there.


Anything else? I assume engine mount holes would be the same. What difference is there between the different spec engines?


Thanks for any info on this,
Steve

 

[ROUSTABOUT]

Hello to all.


Looks like I may have to re-power (or punt) my CC 2185. The engine is a Kohler CH18S spec 62588. If I can get hold of another CH18S, but it's a different spec, what problems am I likely to run into? Are the shaft placements, and intake and exhaust manifolds for example in the same places on the CH18S regardless of spec? Are the pre-drilled holes in the flywheel in the same place (so I can attach my shaft cup)? That would be critical. I figure if the PTO shaft diameter is different, but the same length, I would need to replace the PTO clutch, but no big deal there.


Anything else? I assume engine mount holes would be the same. What difference is there between the different spec engines?


Thanks for any info on this,
Steve

As long as it's around the same size all should work. I always swapped out the 20 horse engines for 37 horse engines and was an easy swap. Just don't get rid of your old one until new one is on and operating. Might need a part or piece off of it.

 

[Steve G]

Appreciate that prompt response, Rous. Wrote that initial post in a hurry. Obviously the intake manifold not an issue, but the placement of the exhaust ports would be. I realize wiring harness would presumably be different. That can be overcome. I assume the exhaust port, shaft location (horiz and vert) would be as shown on the service manual schematic for the CH18S. The hols in the flywheel would need to be the same to hook up the shaft. That's critical. Same on all CH18S engines?

So you foresee no big issues? I figure putting another CH18S, even with a different spec, would be the path of least resistance, barring any of the issues I noted above.

 

[2manyrocks]

I would look up the dimensions of each one just to be sure the new engine has the same mounting and shaft dimensions as the old one.

 

[RandyT]

the ciritical issue will be the crankshaft length and diameter. If the flywheel doesn't match you can swap the flywheel from your old engine. Exhaust ports will be the same, wiring should be the same. Mounting holes will be the same.

Primary differences between the specs, is air filter, crank diameter, charging system, starter system, etc.

 

[Steve G]

the ciritical issue will be the crankshaft length and diameter. If the flywheel doesn't match you can swap the flywheel from your old engine. Exhaust ports will be the same, wiring should be the same. Mounting holes will be the same.

Primary differences between the specs, is air filter, crank diameter, charging system, starter system, etc.

Thanks Randy. Helpful info.

 

[Steve G]

Thanks Randy. Helpful info.

I emailed Kohler last night and had a reply this morning. Senior tech entered my model and spec and generated spreadsheet with compatible replacements. Only one is active, the CH640-3126. Great stuff and thanks again.

Now, who to order from? Experiences appreciated. OPE has that engine and spec supposedly in stock, and also SLE Equipment and powermowersales. Of course, sometimes what is shown online as in stock actually isn't, so I will call first. Any thought on these vendors for an engine, or alternatives? Never ordered a full engine before. Assuming in stock, OPE has best price.

 

[Steve G]

OPE out of stock. Awaiting replies from others. On the up side, this was listed today, about five miles from me. I bought it for $450. A 2185, same model as mine. Same engine, sans the smoke and oil guzzling.

Engine surges, probably carb. and I have an extra, and needs a new starter, which I also have on hand. Otherwise seems solid enough, though not pretty. A second 2185, so "parts on wheels" if nothing else. Might have to lose the hubcaps. Maybe put spinner rims on it.

 

[2manyrocks]

There are cheap carbs on Amazon if it comes to it.

As for shopping for a new engine, I replaced a Briggs on a John Deere with a Poulan branded engine. The mounting dimensions, shaft diameter and length were identical and the engine control wiring connected directly to the JD wiring without any modifications.

I suspect the lawn mower manufacturers shop around for the best deals on engines and make mowers so they can swap brands to get better prices.

If you can't find a direct brand replacement, it could be that another brand engine will fit if you pay attention to the specs for the mounting, muffler placement, shaft output diameter and length.

 

[Steve G]

There are cheap carbs on Amazon if it comes to it.

As for shopping for a new engine, I replaced a Briggs on a John Deere with a Poulan branded engine. The mounting dimensions, shaft diameter and length were identical and the engine control wiring connected directly to the JD wiring without any modifications.

I suspect the lawn mower manufacturers shop around for the best deals on engines and make mowers so they can swap brands to get better prices.

If you can't find a direct brand replacement, it could be that another brand engine will fit if you pay attention to the specs for the mounting, muffler placement, shaft output diameter and length.

In fact I have one of those cheap after-market carbs I picked up a couple of years ago so I could keep mowing while I rebuilt the OEM one. Going to pop that on maybe tomorrow and see what effect it has. I don't see a fuel filter on this "new" machine. Hopefully one is tucked down behind the base of the engine. If none there, that would explain a lot. I have extra fuel filters here as well. Overall, haven't seen anything wrong I don't have the parts and skills to fix. Nothing major anyway, and thankfully zero fouling on the plugs. They have white coating, so it has been running hot, probably from the carb issue.

Still want to re-power the other one. Would be great to have a reserve cub for times like this. May have to do as you suggest and go to another brand. At least the heat's off provided I can get this one running smoothly in short order, and I think I can.