3600 RPM Falls on Cub Cadet 1450.
 

Cub Cadet 1450 RPM not holding at 3600.

The Tractor has Walbro Carburetor with the original linkage. The issue I am having is the Throttle Control (TC) will not hold at the highest RPM (3600) when pushed all the up on the dash. The TC slowly pulls back down, when running, whereby the engine RPM drops down if I do not hold the TC in place.

I am not sure, if it is the way the linkage is setup or if the TC is the at fault. It seems the Carburetor opens up all the way when the TC is at around ½ way, on the dash. The governor spring is not pulled at that point. Only after, the lever is pushed all the way up on the dash, which allows the Governor Spring to be pulled, allows engine to reach 3600 RPM. The Engine does not reach 3600 RPM unless that governor spring is pulled (I am not sure if that's the way it's supposed to work). If I do not hold the lever in place, the spring pressure pulls the TC back down which lowers the RPM.

Any Help would be appreciated! Bob.

Just wondering how you know it's hitting 3600 rpm?

There should be a screw you can tighten up on the throttle control lever pivot, under the dash, to give it more drag, and stop it from slipping back. If I remember, there is friction washers where the screw goes through the lever assy. and tightening the screw increases the friction, and holds the throttle in place !:beerchug:

Agreed, I would make sure all places that your cable is attached are
tight and there is no way the cable itself is moving. Then start looking
into engine stuff.

Ken

Thank You guys, appreciate your replies. I ruled out the cable itself, at the carburetor it is tight there. When engine isn't running it stays in place. It is only when the governor spring is pulled while running, it moves back down to around the middle of the lever. The vibration and the spring pull seems too much pressure for the lever. I think I going to try to remove it and use a vice with some bolts or punches to see if I can tighten that rivet a little, see what happens. I connected a tachometer to engine, the type that wraps around spark plug wire, not the best but gets me into the ballpark.

Attachment 111086

Attachment 111087

I seriously doubt the Governor Spring has enough pull to overcome the friction in the Throttle Lever. If it does, do you have the right Governor Spring?

:bigthink:

That's the million dollar question! I was led believe that the tractor is all original but since i'm new to working on these tractors, you never know what the PO did to get the best price possible when selling. Attached pic is how it currently looks (a little dirty) it shows how the OP has it set up. It maybe wrong, but I don't know! The only thing I do know, is that the lever does not hold, so the RPM is not where it's supposed to be, if I do not hold it in place at the top of the dash.

I would really like to resolve this RPM issue before winter, where I can run the Snow Thrower I restored.

attached pics of how the linkage is connected. The front cable is the choke ad rear cable is the throttle.

Check your engine mounts! Most likely they have failed and the engine is setting too low. I noticed the cables coming through the firewall have "sawed" their way downward on the firewall. In my experience with these models, this will cause the throttle to continuously back down.