QuestionQUESTION: My mountfield mower struck a metal object buried in the ground and stopped violently with a loud bang. I feared the worst, crankshaft snapped but the mower restarted first pull after straightening the blade. Problem is when the engine accelerates there is a sharp pinging coming from the cylinder region. Don't know if I have knocked the timing out or jumped the cam belt. Can you suggest what to check. I don't have a workshop manual for the engine. Thanks in advance.
ANSWER: Hello Scott:
>>If this Engine has a Belt, then the Engine May have Jumped the Belt or the FLywheel Key May be Damaged and Require Replacing.
>>The Following is the Instruction File I Made for Removing the Flywheel from Most Mower Engines. It is the Basics and if you have a Question, Please Ask. Any Input to Make this File Better is Appreciated. ***Disconnect the Coil Wire from the Spark Plug. Remove the Blower Housing (metal engine cover). Remove the Coil. Remove the Flywheel Nut or Starter Cup (Depends on the Model). Now Attach a Steering Wheel Puller to the Flywheel Using the Threaded Holes in the Flywheel. Tighten the Puller. Now Hit the Puller with a Hammer. Repeat this Procedure Until the Flywheel Pops Up or can be Lifted Off the Crankshaft. On Some Models you Can Not Use a Puller and and the Jaws of a Standard Puller will Not Fit. On these Type Engines you can Use a Pry Bar and a Pipe Cap that is Slightly Larger than the Crankshaft. Place the Pipe Cap Over the Crankshaft to Protect it. Place the Pry Bar Under the Thick Section of the Flywheel and Pull Up Against the Flywheel. **BE CAREFUL DO NOT PUT A HOLE IN THE BLOCK UNDER THE FLYWHEEL** Now Hit the Pipe Cap that is on the Crankshaft (covered with the Pipe Cap). Repeat the Procedure Until the Flywheel can be Lifted Off the Crankshaft. *** Be Sure you have the Flywheel Torqued to the Proper Torque (I require the Model and Spec/Type Numbers Off the Engine to Provide the Proper Torque) and Set the Coil Gap to .020in..
>>You can View a Breakdown/IPL at this Site Addy,
http://www.emerichsales.com/ and Select Honda Power Equipment in the Drop Down Under "Parts Look Up" at the Left of the Page. Now Fill Out the "OEM Part Diagrams Look Up by Model Fit" Section.
>>If you Hit a Snag or this Does Not Correct the Problem, I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 3 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. All Follow up Questions are Accepted at Any Time. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Thanks for your prompt help John. The Honda GCV160 engine is an OHC config and does have a cam belt. I need to find out how to access the belt to check the alignment marks. However I am thinking now that the woodruff key may be bent causing the ignition to be slightly advanced causing the pinging/knocking sound which can only be heard under acceleration and not at steady engine speed. I think that if the belt had jumped a tooth that the pinging/knocking might be heard every 2nd rev as the piston clips the valve irrespective of engine speed or acceleration. Do you have an opinion on this theory and how to eliminate the options to home in on the source?
AnswerHello Again Scott:
>>Usuall if the Timing Belt Jumps the Engine may Run, but will have No Power or Usually will Not Start at All.
>>Using the Breakdown at the Site Addy Provided and the Instruction File, you can Remove the Flywheel and Inspect the Flywheel Key.
>>Leave the Timing Belt alone Until you are Sure the FLywheel Key is NOT the cause for this Problem.
>>We can get into Setting the Timing Belt if we have too.
>>The Following is Another Site that may be Helpful to you also.
>>Since this is a Honda, you can Use this Site Addy; http://www.honda-engines-eu.com/en/welcome.html and Select "Service Information" from the Drop Down Menu of the Service Tab. Now Select "Shop Manual". Now Select your Engine Model Range. Now Select your Specific Engine Model and then Download the Shop Manual. The Shop Manual should have the Procedures for Checking and Setting the Timing on your Engine. If Not, then Send me the Engine Model Numbers, Please. With these I can Locate the Correct Manual and Better Assist you.
>>As Always, If you Hit a Snag or this Does Not Correct the Problem, I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 3 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. All Follow up Questions are Accepted at Any Time. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
Hi Again Scott:
>>I Failed to Include the Following.
>>To Install (or Check that the Belt has Not Jumped) a Timming Belt you Look for the Following and Align as Stated. On the Cam, there are Two Lines that should Line Up with the Edge of the Valve Cover Seat Area, and the Crankshaft Keyway should be Perfectly Perpendicular with that Line. Once the cam and Crankshaft are Aligned in the Manner I Just Described; Install the Belt (or the Belt has Not Jumped and the Timing is Correct).
>>Thanks.
Respectfully
John
