CA surging

The surge spring should be in line with the governor rod, at least that's how mine has always been. Do you have an adjustable carb or fixed main jet? If it were running lean that would make it surge. Check for vacuum leaks with some spray carb cleaner around the manifold. Make sure your air cleaner isn't full of ice.

I think the spring is to be hooked on the top side of the rod to a manifold bolt straight above the hole in the rod.

It is a factory spring, I bought it after the surging started some time ago. No blockage, it runs great under load, surges under light load. I will try to mount the spring back on the manifold stud. I set the linkage acording to the service manual. What do you mean by synchronize the gov to the carb?

The cross over arm is out of adjustment. You can put 10 surge springs on it and it will still surge if the cross over arm is not pushing the the butterfly closed against the butterfly stop screw at idle.  It needs about 1/8 inch pressure. You have to bend the arm to adjust it.

mnoonan's pics are correct for a CA. Dick L's advice on the cross arm is also right on. The gap is to be between the throttle shaft and cross over shaft on the front of the engine. Dis-engage them, move your throttle to the wide open position, manually pull the carb shaft to the wide open position; if you don't have the 1/8" gap you need to bend the crossover arm to obtain it.  

You guys are giving me hope. My CA after rebuild and scavagening parts from all over, surges something awful! I will have to keep this in mind till spring when I bring it home from winter storage.

Leon, I had that happen to the little pink tractor. It was surging bad but I could hear a sucking noise. I put a new throttle shaft seal in and have not had anymore problems.

Dick L, I did have the gap the other way earlier today, it ran the same. I couldn't bend the rod back towards the rad so that's why I went ahead and pulled the gov cover, bent the rod in the opposite direction. My CA service book said to make the carb rod 1/16 to long. The I T book I have said to make the rod 1/16 to short. So I thought I'd try both ways and neither seems to help. I will also try to find any vacuum leaks, I don't have any carb cleaner, what's the next best thing to spray on and around the intake and carb? Sorry if this is getting menotinous.

Don't worry about going over it a bunch. It will fall into place when you get the principle.

The governor weights spinning forces the cross over arm back toward the block/head. that pushes the throttle lever back against the stop screw that sets the idle speed. When the throttle lever is set to idle the butterfly is pushed closed manually. If it is not held back by the governor  when you start to move the throttled hand lever the butterfly will open farther than you want and the RPM's will be higher than wanted. The governor is suppose to try to hold the butterfly closed at any time the engine is running. When you push the hand throttle lever forward it tightens the governor spring to overcome the governor trying to keep the engine from speeding up. Without enough governor pressure or enough spring tension against the governor it has to hunt for the proper tension and can't find it and as a result the RPM's go up and down. Or when you move the hand throttle lever just a bit to remove the manual closing of the butterfly it will open up and stay open at a high RPM. It depends in how far it is out of adjustment.
I used to set my puller to surge slightly until the tractor was under load. If you get to much misalignment pressure in the linkage you then loose high end RPM's.

After you get the answer to the whys that make things work it becomes much easier.
  

Sucking air on the throttle shaft seal !!!!!

propane, brake cleaner...just about any flammable aerosol works to check for intake leaks; I like propane. You didn't mention whether or not if you have a weight inside the govenor spring; it is necessary for the govenor to work correctly, and I have seen a few where it was missing.