Small Engines (Lawn Mowers, etc.): wont increase rpms, throttle shaft, throttle plate

Question
QUESTION: Got 18 horse Briggs 31H777 0202-e1 that start real easy and idles good but won't rev up. Had carburetor apart and looks good but you can take needle valve all the way out and nothing happens. On older ones we always had gas running out but not htis one. Had a person tell my siser-in law that it was the govenor but I don't think I want to tare it down unless I know for sure. Thanks

ANSWER: Hello Richard:

From your Description, it Sounds like the Carburetor Needs a Good Soak and Cleaning or the Governor Control Spring (#209 in the Alternator, Controls File) at the Throttle Control Bracket has Broken. If the Governor had Broken, then Engine Would Rev High All the Time. The High End Engine Speed would Not be Regulated by a Broken Governor. The Not Reving Up Indicates; 1- A Broken Governor Spring (Shown in the Alternator, Controls File #209) at the Throttle Control Bracket (Alternator, Controls File #222). 2- A Broken Throttle Cable. 3- A Broken Throttle Link (Alternator, Controls File #202). 4- A Dirty Carburetor. 5- I Alsmost Forgot, this is a Fairly New Problem that has Been Cropping Up Lately; The Bradded Fit of the Throttle Shaft Coming Loose from the Throttle Plate and Allowing the Throttle Plate to Turn But Not Turn the Throttle Shaft (Carburetor, Fuel Supply File #131/141) and Open the Throttle Valve so the RPMs can Increase. Make Sure you Connected the Governor Link to the Carburetor. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model and Type Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John

---------- FOLLOW-UP ----------

QUESTION: Change carburetor and no difference. Everything appears ok. Can the governor cause not to rev up if its set wrong? Thanks Richard Dickson

ANSWER: Hell Again Richard:

If the Governor Control Arm has Been Removed or Loosened from the Governor Shaft, then To Reset the Governor; Loosen the Governor Arm Bolt and Turn the Governor Shaft Clockwise Until it Stops. Using the Governor Arm Hold the Carburetor to Full Throttle. Now with the Shaft Full Clockwise and the Governor Arm and Carburetor Held at Full Throttle, Tighten the Governor Arm Bolt. If the Engine Still Runs Full Throttle, then Reverse the Rotation of the Governor Shaft, but Still Hold the Carburetor at Full Throttle with the Governor Arm. If it Still Runs at Full Throttle, then Check the Internal Governor. Will the Engine Rev Up if you Move the Throttle Linkage at the Carburetor by Hand? Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

---------- FOLLOW-UP ----------

QUESTION: Tried adjusting govenor to no avail. If I set the governor with throttle wide open how can I expect the engine to rev up. Manually the only way it revs is if I have the engine at idle. It seems like when I put in gear and engine mower I lose about a third of my power. Also, how do you check the internal governor?  Thanks  Richard Dickson

Answer
Hi Richard:

If the Governor is Causing Problems, then Usually the Engine Will Over Rev and Not Idle. When you Set the Governor the Way I Instructed, then Engine Will Operate in a Normal Manner. When the Engine is Not Running the Governor Usually Allows the Throttle to Open Full. Does the Engine Rev when you Move the Governor Arm? Is the Link to the Carburetor from the Governor Arm Connected Properly? To Check or Change the Internal Governor, here are the Basic Instructions. This is a Simple Process. Drain the Oil and Remove the Engine to the Work Bench with the Oil Pan Facing Up. I have a Wooden Rest that was Especially Made to Hold the Engine when in this Position. Remove the Oil Pan. After All the Oil Pan Bolts are Removed; Tap Lightly on the Sides of the Oil Pan to Loosen it from the Dowel Pins. When the Oil Pan is Removed, you can See the Governor Resting on Top of the Cam Gear. Lift Off and Replace with a New Governor. Check the Engine Block for Debris from the Old Governor and Wipe the Inside of the Block With a Rag, Until Clean. Set the Governor So it is Resting on the Governor Shaft and Carefully Replace the Oil Pan. Remember to Replace the Oil Pan Gasket. If the Crankshaft Seal Was Not Leaking, then Leave it Alone. It Should be OK. You can Easily Replace it While Mounted on the Machine if Required Later. Make Sure the Governor Stays in Contact with the Governor Shaft while Replacing the Oil Pan. Re - Mount the Engine to the Machine. Refill With Oil. These Instructions are Basic. Your Internal Governor May Differ. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John