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725 Motor Probs

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Since I got the 725 all nice and painted I still cant figure motor out. It will not run smooth.The motor revs up and down.Have tried cleaning carb.switched the spring around on the govenor and still nothing.The motor is a 9hp Briggs.Any suggestions what to do would be greatly appreciated.

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Revving up and down is usually either a governor problem or the carb being to lean. It sounds like you checked the carb so... it may be a governor problem. The internals on these usually do not go bad. There is an adjustment between the arm of the governor on the side of the motor and the shaft that goes into the motor. You can look in the Briggs manual to verify, but my noggin recalls its adjustment procedure being this: Do this with the motor OFF, air cleaner removed. 1)Loosen the bolt on the governor arm (I think its 3/8) just enough to make a movable amount between it and the shaft. You will want resistance so the setting wont change as you tighten the bolt. 2)Hold the throttle fully open at the carb. 3)Turn the governor shaft that goes into the motor fully counterclockwise while holding the throttle open. Turn this using a small standard screwdriver into the end of the shaft. 4)Tighten the nut while holding these positions (this is why you need to barely loosen the bolt, you'll either need three hands or a zip-tie) Anyhow, make sure the linkages and springs are in the proper holes. (per pictures in the manual) The rod that goes between the carb and the governor shaft often gets bent and this will make the governor out of adjustment. Hope this helps some, Dan

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