Right Briggs 18hp Spark Plug?

[kpike52]

Rebuilt B&S 18hp (#421437-013601) will not start. I am not getting a spark across the plug but I do if I remove the plug and arc the plug wire to chassis or motor. The spark plug is a Champion 5861 which is an alternative to RJ19LMC. Is this the right plug?

[Norbert77]

You're not getting spark with the plug in the cylinder? How do you know? I don't know the Briggs motor but a lot of times an engine is rebuilt the camshaft could be out 180 degrees, so it might be firing between the exhaust and intake cycles instead of on compression. Is it getting fuel? Spray some contact cleaner into the carb and see if it does anything

[kpike52]

Tried the carb cleaner and it had no effect.

[msafi65]

Sounds like bad plugs or very weak spark. How far will the spark jump and what color is it? Good strong spark will jump 5-7mm and be bright blue at 3mm. If it's white and won't jump more than 2-3 mm to engine casing it probably won't jump a plug under compression.

[kpike52]

Success!!!
Played with the wire connections and found that the plug sparked when the coil's kill wire was disconnected from the common post. Then rewired to exclude the points from the circuit and she started right up. Apparently this new coil has an integrated timing function. Is that possible?