Gravely Zturn throttle adjustment

[Frankenkubota]

I bought it used with 10 hours on it. Original owner said he didn't like the controls and already had a new lawn tractor in his driveway.

I know nothing about many things so I took a friend who works on lawnmowers. When started, I immediately thought the engine ran at a too high RPM but both the owner and my buddy said it was due to emissions. Ok

The throttle control lever was very tight so during one of our monsoons, i pulled it apart to look see. The choke and throttle levers both mount to and revolve around a rivet and are adjusted by steel cables. The choke was fine. I could barely move the throttle cable by hand, something was wrong.

I could tell none of the hardware had been messed with, no wrench marks or scratches etc. I think my problem was due to assembly errors? I worked on the assembly line for years, at a number of places. You do not want to buy anything made on second shift after lunch!

Long story short, I took the throttle cable off, readjusted it and believe it or not, it worked!

I now have lots of adjustment range and at a lower rpm, the controls are much less twitchy.

I noticed the body parts are all SAE while the kawi engine hardware is metric. I still think that's just crazy and very wasteful! I also noticed they used a lot of self taping screws. They are fine unless the assembly guy/gal puts them in at an angle, which of course they did.

 

[CausticUrbanCoast]

Mowers run at high rpm and have their governor wideopen to compensate for a sudden high load on the deck and to maintain PTO/belt tower speed for clean cutting.

Using it with the rpm down you will likely notice significantly more carbon deposits on your plug and valves.

Is it bad? That is up to you, you will get sudden temperature spikes when it goes on and off load and leans out too far, however I belive your machine is liquid cooled so it will probably be mitigated and handle that behavior for a while.

If you notice ragged grass ends after mowing with new/sharpened blades, you will have to figure out how to increase your pto/belt speed to get your deck at the right rpm.


Edit: oh I forgot, if you have hydraulics on yours, they may be sluggish as your hydraulic pump will not be running at full flow.

 

[Frankenkubota]

Mowers run at high rpm and have their governor wideopen to compensate for a sudden high load on the deck and to maintain PTO/belt tower speed for clean cutting.

Using it with the rpm down you will likely notice significantly more carbon deposits on your plug and valves.

Is it bad? That is up to you, you will get sudden temperature spikes when it goes on and off load and leans out too far, however I belive your machine is liquid cooled so it will probably be mitigated and handle that behavior for a while.

If you notice ragged grass ends after mowing with new/sharpened blades, you will have to figure out how to increase your pto/belt speed to get your deck at the right rpm.


Edit: oh I forgot, if you have hydraulics on yours, they may be sluggish as your hydraulic pump will not be running at full flow.

i don't think the engine is water cooled....if it is, i gotta go find the radiator.

i run it wide open and, per the manual, engage blades at full throttle.

it never had a slow rpm setting or, to use a technical term, bunny mode. i had maybe 10% throttle adjustment, now it's normal.

i'm pretty sure the hold down that clamps down on the outside armored section was also clamping the wire cable.