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Craftsman Blower no spark after replacing spark plug and ignition module


bletzinger's Avatar
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07-17-05, 04:23 AM   #1  
Craftsman Blower has spark now. How do I clean the carb?

I have a 3 1/2 year old craftsman blower vac (model # 358.797340) that was running rough and seemed to be running hotter than usual as well. It finally quit so I checked the usual (air, gas, spark, exhaust obstruction). I replaced the spark plug and left it connected but out of the engine while pulling the starter in the garage (dark) and would only occasionally show spark. I ordered the ignition module and installed it (messy 2 hour job) and still only got a spark 1 time out of 30 pulls. Spark plug is gapped at .025" as required. I guess I'll try another new spark plug but I seem to be running out of options.

Is there another method to test/diagnose spark?

Wife gave the green light to buy another but this one is still in ok shape other than it doesn't run.


Last edited by bletzinger; 07-24-05 at 10:55 AM. Reason: now suspect the carb is plugged
 
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repair_guy's Avatar
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07-17-05, 09:10 PM   #2  
It sounds to me like the ground wire going to the coil has got a short in it or it's being pinched aganist the cylinder fins.If that's the case,a piece of tape could be your best firend.Or maybe even the on/off switch.

To answer your question their are three or four differant kinds spark testers on the market today.The best one that I've found for 2 cycle engines(since they have plastic covers everwhere) is the in-line type.They have a wire you hook into the spark plug wire going to a small (fuse looking) light.And on the other side is another wire long enough to reach a ground anywhere on the mechine.Or just hook to the spark plug while the engine is running,to dagnose an array of ignition problems.And too,these wont ignite any fuel being blown out of the cylinder.


Best of luck,post back with your findings

 
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07-17-05, 10:42 PM   #3  
Maybe a dumb question, but are you making sure the spark plug is in good contact with a metal part of the engine when checking for spark?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
bletzinger's Avatar
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07-20-05, 05:01 PM   #4  
Thanks for your replies. I'll check the ground wire on it and no I wasn't always grounding the spark plug but I could tell it was working when my hand was the ground path!

 
bletzinger's Avatar
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07-24-05, 10:59 AM   #5  
I used a ground wire on the spark plug (because of all the plastic casing) and now have confirmed consistent spark.

I now suspect the carb is clogged. Can someone point me to a thread or post that shows the basics of how to disassemble and clean it?

I can get the 2 covers with seals off but I don't know if I need to go in deeper. Also I don't know if I just spray some carb cleaner in there - I have heard that might not be a good idea.

Thanks

 
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07-25-05, 12:21 AM   #6  
Could be a carb problem, but have a look at the cylinder bolts...make sure they are good and tight, and that the gasket hasn't slipped or blown out from under the cylinder. Common problem. Also, how does the compression feel? A low-tech way to get somewhat of an idea of the compression of the engine is to try picking up the blower by the pull rope. If the rope pulls out so fast that the blower never gets a foot off the ground, you might want to do a little more checking into the engine condition because the compression may be low.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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07-30-05, 05:24 PM   #7  
Cheese,

It turns out that a screw keeping the block sealed for compression keeps coming loose. I suppose i could use lock tite but I'm not sure that is the only problem. I had it running for about a minute earlier today. I'm about ready to get a new one and give up on this one.

Thanks for your help.

Klaus

update: It'll will run after I tighten the screw, prime it with gas in the chamber, but only wide open. I can't get it to idle to adjust the carb. I have the H and L adjustments per manual prior to making final adjustments.


Last edited by bletzinger; 07-30-05 at 05:45 PM.
 
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07-31-05, 10:29 AM   #8  
Azis
If you can get it to run at full throttle, try adjusting the high mixture screw. Adjust it until it just screams, then back off 1/8 or so. If your able to adjust the high, you may need to screw the idle "speed" screw in or hold partial throttle and try adjusting the low. If able to finally re adjust the idle speed.

If the adjustments have no effect or little, more than likely you still have a leak in the cylinder.

 
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