QuestionThe unit has ran fine for years. While using it is essentially idled down and would not start. Engine is Tecumseh 10 hp (4 cycle) Recoil starter. Placing a screwdriver near the plug and in the plug wire I cannot see a spark when pulling the starter rope. Checked for continuity of wiring and all seems well. I there an easy way to check the coil? (I assume there is some ohm value between the secondary and primary.
AnswerThe link below is the Tecumseh repair manual:
http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_L-Head_E...
Briggs and Tecumseh do not publish resitance values in their repair manual. For me, I rarely, if ever, measure coil resistance (ohms). If you have a solid state ignition module, they either work or don't work...no repairing them. As for points, it is quicker for me to test if the points are opening/closing using my old analog voltmeter. If the points are working and no spark then the coil is bad. Most shops these days no longer install points but instead install a new electonic ignition module.
The main thing to test for is an open or short in the primary and secondary windings. Below is some tech data I found online.
Tecumseh Small Engine Coil, 97 grams with 52:1 winding-turns-ratio
Primary coil resistance = 0.621 ohms
Secondary coil resistance = 8,042 ohms
Primary Peak Current = 960 mili amps
Magnetizing Inductance = 17.6 mil henrys
Energy Storage = 8.11 mJoules
Sources: http%3A%2F%2Frocketworkbench.sourceforge.net%2Fign iter%2FCoil_Measurements.xls&ei=PWlXSsmpG4rEMobE_M AG&rct=j&q=Tecumseh+coil+resistance+secondary&usg= AFQjCNFrYl4Pg-9IQHvCVgu7M7bV4fzU7w
http://rocketworkbench.sourceforge.n...iter_blog.html
Can you tell me if you have points or electronic igntion? Don't forget about the safety switches. A bad or misaligned switch will no prevent spark by design.
Let me know if any of this helps.
Eric
