Engine Ramping

[oldhammerhead]

Hello What would be wrong when engine ramps at full throttle,but runs fine at 2 notches back and at idle.Thanks in Advance Steve.

[BigBill]

Check to make sure your governor rod isn't stuck or sticking. It won't hold full throttle but it will speed up when a load is applied.

[oldhammerhead]

Big Bill thanks gov. rod is not sticking every thing is fine only at full throttle?

[Eugene]

engine ramps at full throttle.

Define ramps. I am unfamiliar with the term.

What does the engine do at full throttle?

[oldhammerhead]

Engine runs fine at fast speed but under load engine runs fast and slow not steady.

[Hengy]

Are you saying that it "surges" up and down? That could be either partial obstruction in the fuel circuit, slop in the governor controls (should not be able to move when tractor is off) or a poorly adjusted throttle reach rod.

[oldhammerhead]

Hengy thanks for reply fuel supply is good how much slop are we talking about? please explain adjustment for throttle rod.

[oldhammerhead]

Hengy thanks for reply fuel supply is good how much slop are we talking about? please explain adjustment for throttle rod.

[Hengy]

The adjustment procedure is in the manual (links above), but I'll talk a little about it here.

First, you have to determine if most, or all preferably, of the slop is out of the governor circuit.

Start with the throttle about halfway up on the quadrant. (engine off and fuel shut off)
Next, go to the carb side of the tractor and take hold of the throttle reach rod. Try to move it fore and aft. It it is loose at all, that can cause a problem. If loose, need to determine where it is coming from.

Common areas, where the crossing rod at the front of the engine attaches to the collar on the governor. If there is slop in there, the common cure is to remove the crossing rod, clean the rod and the collar well and place a dab of JB Weld on it. Allow it to sit for a night and it will be nice and solid. If you need to remove it in the future, a little heat with a torch will crack/melt the JB and you can separate it.

Next place to look for slop are the two attachment points for the governor spring at the top of the governor. The holes are often egg shaped and allow a fair amount of movement. Common way to fix this is to remove the spring, drill out the holes a little larger and insert roll pins to make the diameter smaller. The spring should JUST fit in the holes with minimal interference.

Once you have all of the slop out of the system, here is a brief adjustment for the throttle reach rod.

Advance the throttle to 3/4.
Remove cotter pin and pin from the turnbuckle at the end of the throttle reach rod.
Hold throttle all the way to the rear position (all the way open).
Turn turnbuckle on reach rod until the holes line up with the hole in the governor crossing rod.
Turn 1 full revolution LONGER in order to put some tension on the springs.
Replace pin and cotter key.

Your tractor will perform WAY better if you are able to remove all of the slop from your governor system, regardless of whether this is the cause of your surging at 3/4 to full throttle.

Mike

[Eugene]

If this is a new problem, clean the carburetor main jet. Clean the carburetor main jet any way.

[oldhammerhead]

Hengy thanks for the reply,can this be done without removing the hood/fuel tank? And thanks Eugene for the reply, Carburetor was cleaned this spring.

[Posco]

Hengy thanks for the reply,can this be done without removing the hood/fuel tank? And thanks Eugene for the reply, Carburetor was cleaned this spring.

Hengy will be along, but yes, you can do that without pulling the hood. As Hengy mentioned, make sure you clean both surfaces before you apply the JB Weld. Following his instructions made a world of difference in my Cub. And do as Eugene mentioned as well.

Mine was ramping (surging) and I pulled the main jet and blew through it enough to dislodge a small particle that was interfering with the fuel flow. Bingo, problem solved.

[Hengy]

Sorry to be so late to the reply, oldhammerhead. The first fix, the JB Weld to the crossing shaft collar, and the fixing the linkage to the throttle can be fixed with the hood on. If you need to rework the throttle rockshaft at the top of the governor, the hood must be removed. I did this to my 1955 Cub's governor and it doesn't surge and holds VERY well on RPMs throughout its range. Seems to have much more power as well...

Mike