Pro Z 154 RPM Adjustment Settings

I have a Cub Cadet PRO Z 100 EFI 154-S (53RWEFJA050) with a Kohler Confidant EZT750 (747cc, 27HP, EFI) engine. I recently acquired a tachometer. I'm not sure that the idle and running RPMs are correct, so I'd like to set them. Anybody know the specs?

I found the following in the engine service manual:
- "Make sure maximum engine speed does not exceed 3750 RPM (no load)."
- "Standard idle speed setting for EFI engines is 1500 RPM, but certain applications might require a different setting. Check equipment manufacturer’s recommendation."
- Under the section titled "Test for Spark", "Crank engine over, establishing a minimum of 550-600 RPM, and observe tester(s) for spark."
- All the electrical tests are spec'ed to be performed at 3600 RPM.

I can't find anything in any of the Cub Cadet manuals. The only reference I found about the engine was this:
"Engine
Refer to the Engine Operator’s Manual for all engine maintenance intervals, procedures, specifications and instructions"

So do I use 1500 for idle, and 3600 for running? 575 and 3600? Does the running speed stay the same for different decks? I'd hope that they handled that with different deck pulleys.

didn't say which spec and three engine were used on the model.

EZT750-3011.

Looks like 1500 and 3400. Thanks, StarTech.

BTW, where did you find this? Is there a way for someone like me (non industry professional) to look this up?

Kohler dealer portal. Doubt they just let anyone in the portal.

StarTech said:

Kohler dealer portal. Doubt they just let anyone in the portal.

Click to expand...

That's what I figured. Thanks for the info.

Ok... I figured out how to set the idle speed, but not the high speed. The only adjustment on the governor assembly doesn't seem to have any effect. So I searched the engine manual.

From the EFI SYSTEM section of the engine manual:

Idle speed is only adjustment that may be performed on
EFI system. Standard idle speed setting for EFI engines
is 1500 RPM, but certain applications might require
a different setting. Check equipment manufacturer’s
recommendation.

Elsewhere in the engine manual:

Adjust idle speed screw and high speed as
necessary. Make sure maximum engine speed does
not exceed 3750 RPM (no load).

The 1st paragraph sounds like high speed is not adjustable, but the 2nd one makes it sound like it IS adjustable. And StarTech's table above shows differing high speed setting for different versions of the engine.

I used to have an 80's GM car with an early EFI system. It had a cable operated throttle (like this engine), and an idle air screw that allowed the EFI computer to adjust RPM's. I don't see any such valve on this engine. If it had one, it wouldn't need a screw to adjust idle.

So, how do I make the high speed adjustment?

According to this video, I was adjusting the right screw for the high speed, but it didn't seem to have any effect.