Craftsman BackPack Leaf Blower No Spark

StarTech

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Looking at the IPL is cheating ?
Then I do so much cheating I need to be arrested. 40 hrs of doing. Besides it is way my photographic mind works as I need an image to work from.
 

welchs101

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how do you test "kill switch is functioning and you crank it over with a good spark plug" not sure i understand what this means. It kinda sounds like you want to try a new spark plug but if the ignition coil is bad a new spark plug wont help.....right? oh, wait i think i understand now.......try a new spark plug and if it still does not give a spark then its the module........but could it also be that the kill switch as you said is somehow causing the problem? How does measuring resistance cause ignition coil to go bad..........thanks for responding .......trying to learn a little about small engines........
 

bertsmobile1

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Down here you would be told Illustrated Parts list to indicated there was a diagram of some sort , not just a list of parts & numbers .
And yes, if the blower fan has to be removed then most are not an economical repair
Occasionally if I get a newish blower in so I can pull the fan & put some anti sieze on the keyed strait shaft ones they remain repairable.
Most of my customers use the big Stihl blowers & they have all been told unless they pull the fan off, don't bring them in because it can take the better part of a full day to get the fan off.
The shop I get most Stihl parts from smashes the fans &replaces them because that is cheaper than trying to remove them undamaged
 

Hammermechanicman

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Then I do so much cheating I need to be arrested. 40 hrs of doing. Besides it is way my photographic mind works as I need an image to work from.
I'm just jealous of all the documentation you have amassed and have access to.
 

welchs101

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if anyone knows how to test ignition coil let me know.

also, if i have to replace it any idea the model number. i looked up "mtd 7181B fl-56 201004" but nothing really came up.
I got "mtd 7181B fl-56 201004" from the picture i posted above.
 

bertsmobile1

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for all practical purposes they are not testable other than the HT side
Ie plug cap to coil ground
However they are a non repairable part so they either work or they don't work .
You can use a variable gap spark tester to see just how good a working one is . but that is about the limit of it .
 

StarTech

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Basically it is a plug and play part. Disconnect the coil's kill terminal, the one that is the flat none bolted terminal. IF the coil is good the plug (used a known good plug) will spark (arc) when metal case is grounded while pulling the starter cord. IF not then the coil is bad provided your are checking with a known good plug. Now these little 10mm spark plugs are known to go bad quite often so that is another weak in the ignition system to check.

But according the model posted in post 1 the ignition coil part number is 753-04324. The spark plug is a Champion RDZ4H.
 

welchs101

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where did you see the spark plug specification. note: the spark plug that is in the machine now is a firstfire FF-19 is that equivalent to the RDZ4H? Also, do they spec the resistance of spark plugs? i was curious because they tell you to measure the resistance of the plug to see if its any good..........i measure ~ 10k to 11k ohms on mine but i do not know if this is a good reading or a bad reading
 

StarTech

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Firstfire indicates it replaces Champion RDZ19H, RDZ4H.

1641337386860.png
 

welchs101

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thanks.
Question: i was hoping someone knew how to measure the ignition coil to see if it is bad. i looked on line and i did some measurements but i have no way of knowing if based my values if its good or not.

i measured from iron core to post where kill switch goes and i got ~ 0.6kilo-ohms.
i measured from iron core to spark plug boot and i measured ~ 3kilo-ohms............

from what i have seen on others measurements the 3kilo ohms seems ok
but i am not sure about the 0.6kilo-ohms..........this could be good as well. i read somewhere on line that i should look up ignition coil specs
the coil i have on there now is an mtd 7181B........but i cant find the specs on it......does anyone know?
 
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