QuestionQUESTION: I have a B&S 17hp OHV on a Scotts 42 inch lawnmower. What's happening is the engine is building up to much compression to turn over. I have to manually turn the flywheel by hand to get it past the compression stroke. I had the valves adjusted and nothing seems to help. When I open the exhaust valve a little it turns onver fine but I lose a lot of power so I put it back to the original valve settings. Engine model = 311777, Type = 0137-E1, Code = 980305ZD
ANSWER: Hello Erick:
How did you Set the Valves? I Do Not Use the Setting Called for by the OEMs. I have Found that the Following Works Best. Remove the Valve Cover (on the Dead Cylinder for Twin Cylinder Engines). Set the Cylinder you are Setting the Valves on to Top Dead Center (Both Rocker Arms will have Play in them when the Engine is at TDC) When Setting the Valve Clearance. Now Loosen the Valve Adjuster Locks and Set the Intake Valve Clearance to .003in -.005in and the Exhaust to .008in - .010in. I have had Better Performance Out of the Mowers and Less Burnt Valves Using these Settings. 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 Numbers 311777-0137. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Are you Sure the Starter is Not Dragging/Binding Under a Load? Does the Battery have a Full Charge. Are the Battery Connections Clean and Tight? 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 you Question at or Just After 9pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hi John, I tried setting the valves to the above settings, I also checked all the cables, battery and starter. Evrything seems to be ok. I can't seem to figure out what is causing so much compression to build up. The only way to move the engine past TDC is to turn the flywheel by hand. Is there some king of retard device that may be causing the issue?
AnswerHello Again Erick:
If you Reset the Valves as Described, the Starter is Not Binding and the Battery is Good with Good Cable Connections, then the Internal Compression Release has Broken. This is a Rare Occurrence, but it Happens. The Compression Release is Attached to the Cam on Most Model Engines. From Looking at the Breakdown of the Engine, I see the Compression Release is Part of the Cam. 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. Tap Lightly on the Sides of the Oil Pan to Loosen it from the Dowel Pins After ALL the Oil Pan Bolts Are Removed. When the Oil Pan is Removed, you can See the Governor Resting on Top of the Cam Gear. Lift Off the Governor. You Should be Able to Lift the Cam Out of the Block at this Point. Check the Engine Block for Debris and Wipe the Inside of the Block With a Rag, Until Clean. Replace the Cam and Governor. Set the Governor So it is Resting on the Governor Shaft When the Oil Pan is Replaced. (Watch and Do Not Let it Slip Off the Cam) 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
Ps: Just in case you have Lost the Site Addy. 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 Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View.
Respectfully
John
