QuestionQUESTION: I have a Sears Craftsman 7 HP Snowblower with a Tecumseh engine. Model # 143-656272. I recently split the crankcase to try an figure out why it kicks back when pull starting. I'd replace the crankcase gasket when it was about 2 years old. I was concerned I'd gotten the timing off. I've broken the dog on 2 new starters and that gets expensive at $56.00 each. Anyway the book I have shows several different timing layouts. I t also referneces timing dimension as .080 BTDC. I'm not sure what that is? What I alos see inside the engine is a chamfered gear on the crank and a dot on the cam. Now are these lined up tooth to tooth or is it advance one tooth? Or does it need a good set of points? I'm confused as to what to do next. I'm a master auto technician not a small engine tech. I understand car engines well.
ANSWER: Hello Gerald:
The Timimg Mark on the Crankshaft should be a (-) on 1 Tooth and the Cam is Marked with a (.) between the Teeth. The (-) Aligns with the (.) Eaxctly. The Kick Back you Described is Usually Due to the Flywheel Key being Damaged or the Point Set is Not Correctly Gapped. Some Model Tecumseh Engine have an Adjustable Housing for Setting the Timing of the Point Set. Usually if the Point Set Holder was Not Loosened or Removed from the Mower, then it should Not Require Setting (Used on the Older Engines and is a Part of the Coil). Have you Checked the Flywheel Key? Was it Damaged? To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action?sid=PSHx20080114x00001 and Enter the Model Numbers 143-656272 and Click Search. From this Page you can View Diagrams and Parts Lists for you Equipment Using the "View Sub Components" Section Near the Bottom Left. Since this is a Tecumseh Engine, I have a PDF Site Addy that May Assist you Also. http://www.tecumsehpower.com/CustomerService/BSI.pdf . This Site Addy; http://www.outdoordistributors.com/Tecumseh/tmain.html has a Link to a PDF Trouble-Shooting Guide. Simply Select the Free PDF Download for the Tecumseh Trouble-Shooting Guide. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. 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 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: I had removed the flywheel to check the key and keyway when I split the case last year. No damage but I installed a new key anyway. Since I purchased this new in 1977, it's 30+ years old and has never had the points replaced. When the weather is better I'm going to split the case again and recheck the cam and crank timing marks and replace the points. Good Idea? Thanks, Gerry
AnswerHello Again Jerald:
Thanks for the Earlier Comments and Ratings. I am Always Glad to Help. If the Point Set has Not been Replaced in that Length of Time, then the Point Set Contacts are Sticking when they Heat Up and Cause the Miss. Replace the Point Set and See if that Corrects the Problem. Most Likely it Will. If this Unit Does Not have the Point Set but Uses the Old Style Electronic Ign Coil, then Replace the Ign Coil. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. 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 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
