Johnson 6hp, wet sparkplug

first off, i would like to say thanks to all the people who have put time into responding to my previous questions. i'm very inexperienced and the thoughts have been very welcomed. mucho gracias. so, i'm trying to figure out why my engine won't give full power when under load. did a de-carb(i know, i know that wouldn't matter) and tossed in new plugs. i've heard that if a sparkplug is wet then it means most likely that it isn't firing. one plug is dry, the other wet. seems like that would be the reason that it's not getting full power. but, now where do i look to find the inconsistancy? what would be the logical steps for me to follow to find out a little more? and also, how detrimental to the engine is it if i run it with just one cylinder firing? thanks in advance.

Re: Johnson 6hp, wet sparkplug

notsmart said:

first off, i would like to say thanks to all the people who have put time into responding to my previous questions. i'm very inexperienced and the thoughts have been very welcomed. mucho gracias. so, i'm trying to figure out why my engine won't give full power when under load. did a de-carb(i know, i know that wouldn't matter) and tossed in new plugs. i've heard that if a sparkplug is wet then it means most likely that it isn't firing. one plug is dry, the other wet. seems like that would be the reason that it's not getting full power. but, now where do i look to find the inconsistancy? what would be the logical steps for me to follow to find out a little more? and also, how detrimental to the engine is it if i run it with just one cylinder firing? thanks in advance.

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So if were my engine I would check the spark (assuming you checked compression already), and here's a video that describes the procedure for checking spark.

Note, there also an air gap type spark tester (see pic) which is commonly used by this forum because it tests the strength of your spark. The spark tester only cost $6-7 at an auto parts store. The procedure is the same except you remove the spark plugs and one end of the tester clips to engine block (instead of the spark plug). Also, on this type of tester you need to adjust the air gap for 3/8 inch. The spark should jump the 3/8" gap with a strong blue spark. If it doesn?t, you need maintenance on the ignition system. Check the sparkplug cables for cracked insulation. Also, there's a thread on the Top Secret Files that discusses how to change coils and set points.

Hope this helps. -jasper