How to set up governor and carburetor controls on Makita G3500R generator?

There is no idle mode. It runs at a consistent 3600 RPM. There will be a run RPM adjust, just follow the throttle linkage/spring to the governor arm and there will be a second spring on the governor arm that goes to the throttle control adjustment.

Here is some help information I found. But you should do this stuff at your own risk. https://www.auroragenerators.com/blogs/generators/119728961-fixing-portable-generator-that-have-no-voltage-output

If you need further help, I’m available over the phone at https://www.6ya.com/expert/daniel_a4640839dbb7ec58

Donnie,clean and verify all carburetor and governor linkages and springs in place. After cleaning lightly oil all linkages and check for free movement. If all look OK and same problem throttle control could be damaged, governor out of adjustment or internal throttle butter fly shaft stuck/seized open.

The circuit board controller is monitoring the engine rpm and frequency and thus controls the frequency, via the governor actuator, or stepper motor as you say. You can't adjust it. I doubt this is the problem it sounds like either engine is not delivering HP, or there is a stator short causing excessive load / current draw bogging the unit down, incorrect wiring of the stator output. Ha someone taken the stator output leads off the breaker? check the stator resistance and shorts to ground.

No gauges can set the governor . The governor controls the engine at a set speed, as the load on the generator varies so does the engine speed ,the governor tries to keep the engine speed constant.

This action is called governor hunting which generally means the carburetor needs resetting ,a complete internal cleaning or a rebuild
then adjust the high speed and low speed settings by the adjusting screws on the governor spring system (manual may be required for these settings)

Sounds like the governor is not adjusted right or is broken internally. With the engine off make sure the throttle in the carburetor is full speed and unloosen the bolt that holds the governor arm on the shaft and make sure the shaft is turned the same way the carburetor linkage moves to full speed and tighten the bolt.

Is this something that just started happening or has someone worked on the engine or changed any settings? Several things could be happening. Make sure the throttle valve on the carburetor is not sticking. If you can, remove the air filter so you can look through the throat of the carburetor and make sure the throttle plate is moving as well. You many have an internal governor problem, which would be the worst case scenario. There is a static adjustment that can be made externally to the governor, but engine information would be needed for those instructions. If your generator does not have a voltage requlator, the output of the generator will vary with engine rpm.

check your governor and linkage for build up of dirt and grime. You should be able to move the governor by hand, with some resistance from the springs. The governor arm should not rotate about the shaft protruding from the engine.

If governor seems to be in order, and engine cannot maintain RPM that it needs to (hunts), look towards the carburetor being fouled (clean out best you can, but don't soak since it is an EPA carburetor), air cleaner dirty (replace even if looks good), or loss of compression (check with compression tester, should be around 90 psi or better with engine warm).

Can you Regulate the Engine Speed Using the Governor Arm? If Yes, then Reset the Governor. **To Reset the Governor; Loosen the Governor Arm Bolt and Turn the Governor Shaft Clockwise Until it Stops. Using the Governor Arm Hold the Carburetor to Full Throttle. Now with the Shaft Full Clockwise and the Governor Arm and Carburetor Held at Full Throttle, Tighten the Governor Arm Bolt. If the Engine Still Runs Full Throttle, then Reverse the Rotation of the Governor Shaft, but Still Hold the Carburetor at Full Throttle with the Governor Arm. If it Still Runs at Full Throttle, then Check the Internal Governor.** If you Can Not Regulate the Engine Speed Using the Governor Control Arm, then Check the Carburetor Throttle Valve. If the Throttle Control Valve (sometimes called a Flap or Plate) Mounting Screws Came Out of the Control Valve, then you will have No Control Over the Engine Speed. Send me the Model and Type or Spec Numbers Off the Engine, Please. With these I can Locate the Proper Manual and Better Assist you. **The Throttle Cable Attaches to the Throttle Control Bracket. The Cable Moves a Slide that Moves a Pivot. The Pivot has the Spring Attached to it and to the Governor Arm. The Solid Link Connects to the Governor Arm and goes to the Throttle Shaft on the Carburetor. When the Throttle Cable is Moved it Moves the Pivot and the Pivot Pulls the Spring. The Spring Pulls the Governor Arm and the Governor Arm Moves the Throttle Shaft. Usually the Spring is in the Lower Hole in the Governor Arm and the Solid Link is in the Top Hole of the Governor Arm.** If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens