Small Engines (Lawn Mowers, etc.): engine questions, high tension wire, tecumseh engine

Question
Hi John,Tecumseh engine model number is tvs90 43368f ser 8342r..On this engine there is a  electronic ignition.One wire is the high tension wire and the other is grounded on the carburetor.Is the carburetor grounded to the engine?If you move the throttle to the start position,how can this get spark?or is the carburetor not grounded?or when you move the throttle back to the off position,does this ground out to the engine through the governor springs and the throttle spring and then to the engine?
i am just learning this trade and i wanna know a little deeper how things work.
i am very glad there is people like you that take the time to help people out like us.thank you john.
     greg

Answer
Hello Greg:

You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.outdoordistributors.com/ and Select the T. Then Select Tecumseh. Then Select Don't have Part Numbers. Then Enter the Model Numbers (TVS90-43368F). Then Select your Model and Download the File for Online Viewing. The Cut Off Switch is Located at the Carburetor on this Model Engine. The Carburetor is Grounded, but the Cut Off Terminal is Not. The Control Bracket has an Insulated Terminal Assembly (#195). This is the Cut Off Switch. When you Move the Throttle to the Off Position, the Cable Moves a Pivot that Engages this Terminal and Grounds the Coil/Solid State Module (#100) which Stops the Coil from Firing the Plug. This is the Same as On Briggs, Kohler and Most All the Engine OEMs. Welcome to the Crazy World of Air/Water Cooled Small Engines. One Thing Comes to Mind that I Want to Say to you. NEVER be Surprised at Anything that Ends Up Being the Cause of an Engines Failure to Function. I have Put New Coils on Engines and Still had No Fire. I went through All the Diagnostics and KNEW the Coil was the Problem. 5 Coils Later; I Accidently Put One on Upside Down (yes they have an Up and Down Side if the are Solid State Ign Coils) and the Engine Scared me to Death. It Fired Right Up. LOL. I Contacted the OEM and They Did Not have Any Knowledge of this Problem. Upon Further Research, I Found Out that it was a Complete Run of Ign Coils. They All had the Same DOM and Batch Numbers. They Worked Really Good, I Just had to Mount them Upside Down. This is One of Many Headaches I have had Over the Years. Let me Add; I Loved Every Minute of it. The Challenge of Actually Coming Across an Engine that had a Complicated Cause for a Simple Problem. Thanks for the Good Words. I Enjoy Assisting Everyone As Much As Possible. Sometimes it is Difficult to Do, without a Breakdown or Actually Seeing the Equipment, I But I Try to Cover All the Most Common Cause First and Slowly Work through the Diagnostic Process with Everyone. Sometimes I can Take the Time to Go "In Depth" as I am with you; but Mostly I have Files that I Copy and Paste for the General Descriptions and Instructions. It's been Great and I Hope you Enjoy the Experience. Send me a Question Marked Private and I can Talk More if you Need to. 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. Thanks.

Respectfully

John