318 governor-carb issue

Advice Needed

I have a 318 with a B43g engine in it. I just finished rebuilding the engine and it runs smooth with no hunting and purrs like a kitten all across the throttle range.

It has a front PTO for the mower deck and a rear PTO for the MCS. When I turn both PTO's on the engine slows down for a second due the increased load and returns to normal speed as expected.

Everything is working as expected and I would not know I had a problem if my lot was level. The problem is when I go up hill. The engine starts to slow down and then the governor arm responds due to the load and opens the throttle baffle in the carb as expected. The problem is the carb does not respond to increase the speed of the engine unless I bring the hydro lever back towards the neutral position and reduce the load on the engine. I almost have to stop the tractor.

I have compared the governor operation to my other 318 and it appears to mechanically work the same up to the point where it opens the carb baffle but the speed of the engine does not increase. I have tried all governor spring and arm settings but none resolve this issue and I have returned the settings to as the engine manual describes.

I took the carb off today and I am going to really clean it. I just wondered if the float settings could cause this problem or does it sound like a clogged jet? Just as FYI information the input idle needle valve setting does not cure this problem and is now set at 1.5 turns. The carb also has a fixed main jet…not adjustable.

Any input would be appreciated.

John