# weak spark redmax



## garyvmont (Nov 28, 2011)

i have a redmax trimmer that won't start. the fire appears veryweak with a new prescribed 10mm plug but brighter with an old echo plug. now here's what i didn't expect... i can hold the plug in my hand and lay the back of my hand on the cylinger and the plug fires with very little shock. my hands are dry. ??
why would the echo plug fire stronger than the redmax? gaps are both .025"
any good way to test a coil? i checked ressistance in both windings... all i can say is there is some. coil gap is ~ .010" ground/kill wire is disconnected at the coil. plug wire appears intact.


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## 30yearTech (Sep 14, 2006)

It's impossible to determine the strength of the spark simply by looking at it as it jumps the gap on a spark plug. Use a gap type tester and if you can see or hear the "pop" when the spark jumps the gap, then it's good enough to start and run the engine. 

Have you checked the compression?
How old is the fuel?
Have you tried starting with a prime?


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## garyvmont (Nov 28, 2011)

thanks... the compression "feels" pretty good but i need to make a 10mm adapter for my tester from a plug and antifoul adapter... got the parts, need to weld it up.

i also need to bring my gap type plug tester back from indiana when we go home for xmas. all i have down here is a bulb type. i did get a pretty bright spark on the 10mm plug after i tightened up the coil gap as much as possible.

didn't fire with carb cleaner in the carb or under the plug. (has not been a test i rely on)

got the carb in cleaner as we speak 

the fact i don't get shocked when i hold the plug was a real shock to me... I've been japped several time not trying to "feel" for the strength of the spark.


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