OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Honda Engines Honda GC160 governor help needed

Good day, thank you for letting me join this forum.

I have a Honda Gc160 engine on a pressure washer that I have had for a few years now. I bought it from a friend for cheap because it had an issue and he bought a new one. Basically, the pressure washer would work fine until you have it in bypass mode (wand trigger not depressed) then the rpms would shoot up a lot. My friend had rebuilt the carb awhile back and apparently did not reconnect the governor correctly.

I got around to trying to see what is going on and see that the governor arm was not attached to the governor arm shaft at all.



I searching for a diagram of how this is supposed to be attached, I saw reference to a governor arm nut, which I do not have nor see how it would attach. There was this pin that was on the shaft which I can only assume is supposed to retain the arm on the shaft?



Can someone help me with how the governor is supposed to be attached? Also is this slot in the shaft supposed to be facing this way?




Top view




I believe this is the serial # of the engine if needed.



I am going to order a new governor spring as the current one looks mangled. I believe this is the correct one if someone here can verify or tell me otherwise.

spring

Thanks in advance for any help and let me know if need any other detail.

Hi Raul, welcome to Outdoorking.

Your governor arm needs to be installed on the governor arm shaft, but first you have to install the R clip on the shaft. Here are a couple of instruction drawings that show how it works and how to put it together. First, the governor arm shaft:


As you can see, the governor uses a centrifugal fly-weight system inside the crankcase. Hopefully you do not need to go in there and do anything, you just need to pull the shaft outward, rotate it clockwise as far as it will go (using a wrench across the flat on the end of the shaft), then put the R clip on, with its straight side laying in the groove in the shaft. Unfortunately from what you have said, the engine has been run with the governor arm and the R clip not fitted. While that was going on there was nothing to prevent the governor shaft from rotating, allowing the governor slider to fall off the governor shaft inside the crankcase. If that has happened, the crankcase will have to be dismantled to put it back on.

Next, you need to fit the governor arm:


As you can see, the lower end of the governor arm requires a pinch-bolt and nut, which appear to be missing from yours. I suggest you get these parts from a Honda dealer. Note Item 5 in the assembly instructions, which tells you how to get the governor arm into the correct rotational position before you clamp it.

You should now be able to gently pull the governor arm to the right and left, verifying that the throttle butterfly valve on the carburetor moves all the way from full throttle to idle. This verifies that the previous tenant, who seems to have been a bit heavy-handed, has not done any harm in that area.

When you have assembled those parts, it is time to fit a new governor spring as shown in the second diagram. I agree that the previous tenant seems to have mangled the old spring.

If any of this is unclear, please ask and I'll try to clarify further. Please come back in any case and let us know how it is performing.

Grumpy,

Thanks a million for the reply. Fortunately the R clip was on the shaft when I began to try to fix it, it was just missing the pinch bolt & nut so the arm was off the shaft.

I reconnected it per your directions with a new pinch bolt & nut and did the adjustment. The pressure washer is working much better now and when in bypass mode it rpms just surge up and down a bit, not revving like mad as before.

The only remaining issue is with steps #7 & #8 of the slow adjustment as it doesn't seem that my throttle valve closes fully, as though there were slack in the mechanism to push it to close. I am suspecting it may be due to the knackered governor spring, which I ordered along with a throttle return spring.

Thanks again for your help and if you have any other suggestions regarding the throttle closing issue I am all ears.

Thanks for the update, Raul. I'm very glad the governor slider had not come off the end of the shaft inside the crankcase. If it had, the governor would not work at all, and the engine would run at self-destruct speed any time the speed control was set at anything above idle.

I'm accustomed to pressure washers being run at full governed speed at all times, rather than having an operator-accessible engine speed control. On the washers I've seen there is a screwdriver adjustment of the full governed speed, but no need for the operator to interfere with it except during engine tune-ups: in service it always runs at full governed speed. I'm aware though that some of the popular units in the US do have an operator-accessible speed adjustment lever, though I'm not clear on why.

The system for controlling engine speed stretches the governor spring when you want a speed increase, and relaxes it for a decrease. The centrifugal governor inside the crankcase pushes the governor slider in the direction to close the throttle, with a force proportional to engine speed. The centrifugal governor and the governor spring thus oppose each other, and reach an equilibrium at some speed where the force from the centrifugal governor is exactly equal and opposite to the force from the governor spring.

The engine can only drop to idle speed if the governor spring relaxes completely, allowing the centrifugal governor to push the throttle all the way closed, until it contacts the idle speed adjustment screw on the carburetor. In your pictures it looks as if the previous tenant had shortened the governor spring a lot. In effect this would have set a minimum speed the engine can run at. With the correct, full length governor spring, it should be possible to fully relax the governor spring, allowing the centrifugal governor to push the throttle right back to idle position.

Note that the way I use a pressure pump, the engine speed is fixed and simply runs at maximum speed except when I stop the engine, which I routinely do whenever I won't be spraying for a minute or two. It seems to me that it is as easy to stop and start the engine as it is to change the engine speed setting down and then up again. Most of the larger, commercial pressure washers simply run all the time at full speed - their pumps are rated to tolerate the frequent dumps of hot water required to keep the pump from cavitating. Light duty pumps for home use treat the hot water dump more as an emergency protection than a normal part of operation.

I have never attempted to run a pressure pump with the engine idling. It is possible that the basic load imposed by the pump will be more than the engine can support at idle, so the engine would stall. That may be why the governor spring on your pump engine has been shortened.

I was reading this thread and am having a similar problem. I was hoping for a bit of basic information. I have a Honda gc160 motor on a pressure washer and my governor arm does not move back to the idle position, it stays in full throttle position. When I push the control arm down to slow, the idle spring just goes slack. There seems to be nothing to push the governor arm back away from the carburetor. What is supposed to move the governor arm to the slow position...is the governor control arm spring supposed to move it (looks like it only is used to pull the arm to the fast position, but not meant to push it back), is the throttle valve on the carb supposed to push it back, or is there supposed to be tension on the governor shaft that rotates it back counter-clockwise?

When the governor arm is off the shaft (and the r-pin removed), the shaft will turn freely counterclock wise, and can be rotated back clockwise...but there is no tension on this shaft.

Thanks