Way off topic - Honda GC190

[atpchas]

I've been working on a Karcher pressure washer powered by a Honda GC190 engine. I can't get the rpms down to a safe range to run the washer. Unless I manually pull back on the governor, the engine races along at over 5000 rpm and it should be closer to 3000. The engine starts easily, fuel is good, carb is new. I've never really grasped how governors do their "magic," so I'm at a loss as to how to remedy the problem. Before I throw in the towel, any suggestions from those with more experience with these engines?

 

[Conquistador3]

I have experience with both GCV and GX engines, but I am yet to see a GC up close. Could you post a picture of the rocker arm? If it's similar to the one on the GCV, this will be quickly sorted.

 

[HarleyT]

Generally, it is a balance, the gov mech presses the throttle closed.
The faster the engine runs, the more the gov forces the throttle closed, a pressure washer runs at a set rpm, so there is no varying control on the rpm. Snap a pic or two, so we can see what you have.

 

[atpchas]

Here are some pictures. Let me know if a different view would be helpful.


The black hose (impulse?) does not interfere in any way with the governor rod.


Closeup of the governor mount.


Connection to throttle.


Throttle connection viewed from top.



Tensioning spring from frame to governor rod.

 

[HarleyT]

the linkage to the carb doesn't look right, but I cannot tell much.

 

[HarleyT]

Here is one out in the shop.

 

[HarleyT]

Can you move the throttle plate on the carb by hand?

 

[atpchas]

Can you move the throttle plate on the carb by hand?

Yes. To keep the engine from over revving, I have to pull the governor rod to the right (using our pictures above to distinguish right from left) which, of course, moves the throttle plate.
The only difference I see between your throttle connection and mine is the whether the spring lies next to the round rod or has the rod inside it. Not sure what purpose that spring serves.

 

[HarleyT]

Mot sure that the pic I put up has the setup correct, the washer was brought in for pump problems, so I have never heard it run.
And it is too cold for me to mess with it. That spring doesn't do much..

What all has been done to your project? What is the history?

 

[atpchas]

What all has been done to your project? What is the history?

I'm working on it for a friend. He made the big mistake of loaning the washer to a friend. When it came back, it was down on pressure (put in a new pump, this one was not designed to be rebuilt easily) and the engine was racing. The carb that was on the washer had no adjustment screws whatever but did run. After making no progress on the racing problem with the old carb, I got a replacement with an idle adjust screw and a another adjusting lever whose purpose I can't figure out - it doesn't appear to affect anything when turned. In any event, the new carb made no difference in keeping the revs down.
Assuming the governor mechanism isn't completely FUBARed, I suspect the solution may lie in adjusting that connection at the base of the gov where it attaches to the rod coming out of the block. I'm reluctant to mess with that until I have a better idea of what I'd be changing and what effect to expect.

 

[HarleyT]

So, the gov. rod has never been messed with? Just curious, because it came in with pump trouble, but now it has a gov/rpm problem. which is why I was curious about the history....

 

[atpchas]

So, the gov. rod has never been messed with? Just curious, because it came in with pump trouble, but now it has a gov/rpm problem. which is why I was curious about the history....

The rod has not been messed with by me. Lord only knows what was done while the washer was out on loan. When friend brought the washer came to me, it already had the rpm control problem in addition to the pump problem. I suspect the pump was done in either by the over revving or perhaps being allowed to freeze. In addition to the damage borrowers can do to equipment, there is almost always a complete loss of history of things done (or not done) to the machinery. I'm sure that's nothing new to you.
I'm trying to fix the rpm issue before it gets a chance to possibly ruin another pump.
Chainsaws are soooo much easier to diagnose and fix....

 

[HarleyT]

Well, they might have tried to mess with the r.p.m. to get some pressure. The static gov. adjustment might be all you need to do.
Need some engine info to try to look up info.

 

[atpchas]

Well, they might have tried to mess with the r.p.m. to get some pressure. The static gov. adjustment might be all you need to do.
Need some engine info to try to look up info.

Is the engine info anything I can provide? If so, I'd be happy to.
Have already noted it's a Honda GC 190. Sticker on gas tank has these strings:
GC190LA QHAFR280
GCAAA 1862724

 

[kevin j]

Is the governor linkage phased backwards, such that thepulling of the internal mechanism actually pulls carb throttle open instead of closed?

Seen that many times, especially on air vane governors. Might be possible on the internal weight type governors.

Get it to idle and figure out which way the internal mechanism is turning the outside arm as the speed increases, then figure which way the throttle is being moved.

 

[atpchas]

Is the governor linkage phased backwards, such that thepulling of the internal mechanism actually pulls carb throttle open instead of closed?

Seen that many times, especially on air vane governors. Might be possible on the internal weight type governors.

Get it to idle and figure out which way the internal mechanism is turning the outside arm as the speed increases, then figure which way the throttle is being moved.

All I know is that the carb is pinned wide open and I have to pull on the governor rod to lower the revs. I've not observed the governor to ever lower the revs unless I was moving it by hand.

 

[HarleyT]

 

[atpchas]

Interesting vid. Looks like I have a project for tomorrow afternoon after a morning attacking a small sea of poison oak. Thanks for the link.

 

[Big_Wood]

all you need to do is loosen the nut of the governor shaft and adjust it while it is running. tighten the nut and your done. i adjust the governors on briggs to turn max RPM's for lawn mowers. i get them free at end of driveways on spring cleanup so i just make them sing. real nice cut even when the grass is soaked lol. they seem to last just as long too but i'm no commercial grass mower.

 

[Conquistador3]

Remove the air filter so you can see the carburetor butterfly valve.
While keeping the valve closed, undo the governor arm bolt and gently rotate the arm clockwise. Refit air filter, start the engine and see if engine rotation speed is adequate. If it's still too high adjust again.

Two words of advice.
First, carburetors used on GC and GCV engines have no adjustments. The only thing that can be done is changing the main jet if operating at altitude.
Second, some of the latest engines from these two families are equipped with an auto-choke. If that's the case, engine speed must be set after warming the engine up.