Kohler CV491S Governor Problem

[Freddie21]

Hello All, I picked up a Scotts Sabre by Deere 1752 with a Kohler Command 17.5hp single on it. Numbers are in the attachments. The governor went bad on the previous owner and he had it disabled by rotating the governor shaft CW and adjusting the throttle plate assembly. I replaced the broken governor gear and pawl and adjusted the arm fully CCW with the throttle being held wide open. The engine has always run very smooth and easy to start. Just no balls when under load.

At this point I have the max rpm at 3500 and min at 1400. The engines starts and runs smooth, but it SLOWLY BUILDS to speed and there is no governor activity even on cold days. When put to idle then increased quickly, the speeds up slowly. The governor spring was in the top most hole, I moved it to the middle and no effect. I can push the arm more CCW as the engine is at max speed and it gains a few more rpm. Most of the engines I have worked on will surged slightly until warmed up. Not this one. It does not bog down when the manual PTO is engaged. Can't test in high grass as there is none.

The throttle cable is adjusted so it opens the butterfly fully and the max RPM was adjusted with the whole throttle assembly plate. The service manual shows the procedure to adjust the is plate. It shows two styles, neither of which is this one. I think I'm close.

Thanks for the help,

 

[ILENGINE]

If that is the throttle cable going up and then back down in the 3rd picture how tight of a bend it that cable making. Could be the cable isn't moving freely and slowly crawls through the conduit to increase the throttle instead of moving quickly when the throttle control is moved.

 

[Freddie21]

No, that's the PTO cable. Thanks for responding

 

[Rivets]

Probably time to stop, take a nap, and start over, starting with the static governor setup. Looking at your picture the speed control bracket looks like the figure 5-24 on page 5-15 of the service manual. I would redo the setup procedure starting on page 5-13.

 

[Freddie21]

OK, will do.

 

[Rivets]

I would add, “Don’t say to yourself I did it like this before “. Say, “I know how to do this, does the manual say l’m dumb and should do it this way”. If a customer came to me with this problem, I would say “don’t tell me what you did, let me figure it out from scratch “. When I get a problem and can’t figure out what I did wrong, I sleep on it and then start over like I’ve never touched it yet.

 

[Freddie21]

Got it, thanks

 

[Freddie21]

Hey Rivets, I'm gonna adjust that bracket later today. Another issue with this engine is if I adjust the idle speed lower than about 1500 rpm, it runs very rich and blows black exhaust. Anything above that speed and it runs smooth and clean.

 

[Freddie21]

Well Rivets, you were spot on again. The tech used the 590 manual which is similar, but didn't show the correct bracket. Everything works well, including the governor, but the max rpm I get is 3900. Low is at 1400 rpm and no lean condition. Plate is adjusted all the way up. I messed with different cable positions and nothing helped. I'm hoping this will be enough for hydro and blades. Moving the governor spring lowest hole causes surging. Middle position it is.

If you have a way to increase the rpm's let me know, otherwise thanks for all your assistance.

 

[StarTech]

You are already way above spec'd max rpm if you are at 3900 rpm. Slow her top speed down.