CV490S Throttle & Governor Linkages

[GearHead36]

I have a Husqvarna CZ 4817 Zero Turn Mower (968999220) with a Kohler Command CV490S. It has the common leaky carb problem, so I I'm taking a gamble on a cheap Amazon carb. However, as I'm putting it back together, I notice that the throttle is not wide open with the mower not running. I can move it by hand to full throttle, but the governor is not doing it on its own. I'm wondering if I'm missing a spring somewhere. Can someone provide a diagram of the throttle & governor linkages for this engine?

If not an external spring, then what would be the problem? I'd guess something internal.

Maybe this explains why I've had problems with this mower bogging under load. There have been times when the grass was thick, and when mowing up a slope, I would have to slow down. Maybe it's hasn't been getting full throttle for a while.

Edit: Resolved. Go to my next post for the answer.

 

[Mark H_NO]

Replacing the carb(and I've had good luck with Amazon carbs) means you probably need to adjust the governor. Here's a video. I am not an expert at governors, just learning them now.

Hopefully someone with more experience will show up pretty soon.

 

[Rivets]

Maybe this manual will help you out. https://resources.kohler.com/power/kohler/enginesUS/pdf/tp_2339_d.pdf

 

[GearHead36]

Never mind. Apparently I'm an idiot. I don't know what happened, but it's working now. I just went out to the garage. I was going to make a photo of the linkages to see if I could see what was wrong, and... it's working fine now. At least I think it is. I don't have it running yet.

When I first installed the new carb, I had the choke and throttle linkages reversed. Maybe that's when I noticed that the throttle wasn't fully open. Or maybe I checked it before I snugged the carb to the block. The linkages are correct now, and the carb is snugged up against the block, and with the throttle lever at max, the throttle linkage to the carb has the throttle at wide open with a bit of pressure on it, just as I expected.

On a related note... where do I find the spec for RPM setting for the governor? The engine manual says 3750 max no load, but to check the manufacture's spec for the actual setting. I have an operator manual for the mower, but it doesn't mention this.

 

[hlw49]

I have owned two of those mowers.In fact it was the first ZTR I ever owned. One of my sons is still using one now. The only thing I can say bad about the little mower is it should have had a 20 hp engine on it. The other mower I still have and am about to put a 20 hp engine on it and put it back to work. That little CV Kohler single is the best single engine ever built. Post the spec no and someone can probably find the top no load rpms for you.

 

[kbowley]

Max rpm's is 3,400 to 3,600 RPM's. Don't run it at 3750. Those engines are bulletproof and have plenty of power. I wouldn't mess with the governor until you get it running properly. Do you have a Tachometer to check it accurately?

 

[GearHead36]

The only thing I can say bad about the little mower is it should have had a 20 hp engine on it.

Agreed. My CZ 4817 (48" ZTR) is underpowered with this engine. Or maybe it just needs to be running right. I just know that the last time I used it, I had to slow to almost a crawl when mowing thick grass uphill. I bought a replacement for it. One of my main criteria was more power. My "new" mower (it's used) has a 54" deck, but also has a 27HP engine. The "new" one has 41% more HP per inch of deck. The RPMs will drop slightly in thick grass, but it never bogs, and I never have to slow down. I don't blame the 17HP Kohler, though. Husqvarna should have spec'ed a more powerful engine for this mower. 20 HP would probably be enough.

Max rpm's is 3,400 to 3,600 RPM's. Don't run it at 3750. Those engines are bulletproof and have plenty of power. I wouldn't mess with the governor until you get it running properly. Do you have a Tachometer to check it accurately?

Yes, I have a tachometer.

I have also installed a cheap Chinese carb from Amazon, and it seems to run well. It just seems like the RPMs are low.

Another question, this time about the carb. The OEM and Amazon carbs have two adjustments... idle and air. I adjusted the idle, but how do I know when the air screw is properly adjusted? I can do adjustments on 2-strokes, but they're much more sensitive to air adjustments.

 

[slomo]

Agreed. My CZ 4817 (48" ZTR) is underpowered with this engine. Or maybe it just needs to be running right. I just know that the last time I used it, I had to slow to almost a crawl when mowing thick grass uphill. I bought a replacement for it. One of my main criteria was more power. My "new" mower (it's used) has a 54" deck, but also has a 27HP engine. The "new" one has 41% more HP per inch of deck. The RPMs will drop slightly in thick grass, but it never bogs, and I never have to slow down. I don't blame the 17HP Kohler, though. Husqvarna should have spec'ed a more powerful engine for this mower. 20 HP would probably be enough.


Yes, I have a tachometer.

I have also installed a cheap Chinese carb from Amazon, and it seems to run well. It just seems like the RPMs are low.

Another question, this time about the carb. The OEM and Amazon carbs have two adjustments... idle and air. I adjusted the idle, but how do I know when the air screw is properly adjusted? I can do adjustments on 2-strokes, but they're much more sensitive to air adjustments.

Is it under powered or do you need to cut more often?

Revs dropping in thick grass might be from dull blades. There is a lot more to blade sharpening than just shining up the bevel and reusing.

Are you cutting wet grass? Dry grass is easier to cut than wet.

 

[slomo]

I have also installed a cheap Chinese carb from Amazon, and it seems to run well. It just seems like the RPMs are low.

Could have several dead deck bearings/spindles causing the low power.

 

[GearHead36]

Is it under powered or do you need to cut more often?

Revs dropping in thick grass might be from dull blades. There is a lot more to blade sharpening than just shining up the bevel and reusing.

Are you cutting wet grass? Dry grass is easier to cut than wet.

It COULD be that I need to cut more often. The problem usually occurs on my sister's yard. Her grass is thicker than mine. She has a boyfriend that usually mows for her. I do it when he can't, and the grass gets out of hand.

Blades are kept sharp.

I never cut wet grass.