L2900 sticking throttle

[Jack Lithgoe]

L2900 throttle sticks but can be un-stuck by lifting the foot pedal or manually pulling the throttle by hand (under the hood) The linkages have been disconnected to rule them out. Just feels like the throttle is tight or has a sticking point. Is the cap nut on top of the throttle body a friction adjust?
Some problems are from abuse, others from lack of use, but WD-40 didn't fix this problem.
Thanks for your wise counsel!
Jack

 

[85Hokie]

WD-40 is a water repellent.....no bad stuff if it is all you have but not the best lubricant you could use.

Not sure on your model - but some do have a nut with a friction washer under that does control the movement. Not sure in your case.

So all the linkages work freely when unhooked?

 

[North Idaho Wolfman]

So you took the linkage off at the speed control plate and that's where it's sticking?
Or is the linkage sticking before it gets to the throttle control plate?

 

[Jack Lithgoe]

I removed the foot throttle rod link and the hand throttle rod link from the common connecting link mounted on the firewall. The 30 inch offset connecting rod is now only connected at the throttle body.
I can advance the throttle easily by hand, but I have to apply more force to disengage the throttle (reduce speed). This operation is Engine OFF.

So now imagine the linkages are hooked up. I can ADVANCE the throttle with either the hand lever or foot pedal, but I can only REDUCE power by putting my toes under the pedal and lifting it up. When I get it past the rough spot it springs back to idle speed. Normal operation would be a spring return of foot pedal like any accelerator pedal. This operation is Engine RUNNING.

All places where metal can move has been lubed with Lithium spray grease, or WD-40. I tried both separately.

I hope this description is clear. I use the hand lever for PTO operations and longer travel, but just moving around the yard I use the foot pedal and don't want the throttle sticking and running into my shed. Although the clutch would prevent that, I just like a spring unloading accelerator.

I don't want to remove the throttle body to look for a possible broken spring, if it could just be a too tight friction connection. I don't have a manual or diagram of the throttle guts.
Thanks,
Jack

 

[Jack Lithgoe]

So you took the linkage off at the speed control plate and that's where it's sticking?
Or is the linkage sticking before it gets to the throttle control plate?

There could have been a short answer to your question NI Wolfman, but I started troubleshooting at the dumb end and worked forward to the throttle control plate. I feel the sticking at the TCP.

Tx

 

[North Idaho Wolfman]

Just for clarity:
With the rod removed at the throttle control plate, does the throttle lever stick?
If it does there are 2 nuts that lock together, unlock the top and then turn the bottom nut 1/4 or so, spray all around with lube, does it now spring back?
If not turn another 1/4 turn, try again.
If not very lightly tap the top of the bolt that holds the lever, try again.
If not, you need to pull it off and inspect, could be the shaft is corroded and needs polished and lubed.

Now once that is working, with hand throttle in idle position check that the foot throttle will pop back up on it's own, as it is spring loaded, if it doesn't you will need to fix that.

The hand throttle does not have any spring motion in it, it lock in place always.

 

[Jack Lithgoe]

Seems like a good plan. If tomorrows weather permits, I'll get on it. Thanks for your help!