Craftsman Gas Leaf Blower Won't Start


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Old 05-17-07, 04:00 PM
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Craftsman Gas Leaf Blower Won't Start

I bought this blower in 2004, and it worked OK for about a year, then wouldn't blow at full velocity unless I held it upside down - turning it rightside-up made it stall. I did that for about a year until I got fed up and took the thing completely apart to determine the cause, even though I know almost nothing about engines.

What I found was a large build up of carbon, or something like it, at the start of the aperture that connects the piston's tube with what appears to be an exhaust muffler or something. After cleaning that gook out of that hole it worked like new...for about two days. I was using it for about an hour straight when it slowly and consistently lost power/velocity over the course of about 25 minutes, ending with the motor stopping altogether. About half-way through that 25 minutes I refueled, and noticed at that time wisps of smoke in the gas tank hole as I filled it. (eeek!)

I now can't get the thing started. I took the "muffler" off again and checked the hole that was plugged before and it is still clean.

Any ideas what would cause an engine to slow down like that and stop? I suppose I'll have to take the whole thing apart again, which isn't straightforward, but knowing where to look would be a big help.
 
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Old 05-17-07, 07:12 PM
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Always start with fresh fuel for small engines(fresh from the pump not fresh fron the can from last year or before) each season. Besides the port there is also a spark arrestor in the muffler that should be cleaned.
If the exhaust port carboned close within one year you may be using to much oil in your fuel mixture, mix according to the mfg recommendation and make sure you are using good 2-cycle oil, I always suggest using Stihl 2-cycle oil it has everything your engines needs and nothing it doesn't. At 3 years your fuel lines are most likely shot and you could use a new fuel filter. Check these items and post your results. Have a good one. Geo
 
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Old 05-18-07, 03:10 AM
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I've seen dozens of these Poulan/Craftsman units with a loose cylinder and/or carburetor which will, certainly, create a power loss. And, possibly, a scored/scratched piston and/or cylinder bore due to the lean condition such will cause. Pull the spark plug wire off the spark plug, grab ahold of the spark plug and, with suitable force (but not excessive to cause breakage), check if the cylinder seems loose to the crankcase. Now remove the air cleaner cover and grab ahold of the cleaner base/carburetor and feel if the carburetor seems loose to the cylinder. If either are loose, you'll need to remove the screws that hold each to their respective counterparts and use blue Loctite to keep the screws from backing out again. It is also advisable to replace ALL related gaskets when servicing either. If either are, indeed, loose, you should first remove the muffler (again) and inspect the condition of the piston and cylinder before you spend any time or money for if there is considerable damage, it will be time to buy a new unit.
 
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Old 05-20-07, 06:56 AM
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Partly debugged

Well I took the whole thing apart again and found nothing loose or carbonized, although I did find that the piston, and the cylinder to a lesser degree, were pretty heavily scored. I believe this must have been due to the carbon deposits that were loosened up during the last cleaning, although I can't say for sure. In any case, the fact that I can't get it to turn over at all or even come close indicates to my unknowledgeable mind that it might be something else. geogrubb's idea about the gas being old is the next thing I'll check. Yes - I should have checked that first, but I just remembererd that the gas mixture was not new last night - left over from last fall.

Thank you for the help provided.
 
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Old 05-20-07, 07:36 AM
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You can't get the engine to spin over? Even with the spark plug removed? You could potentially have a crankcase full of gasoline and would then cause a hydro-lock situation where the engine would not crank over unless the spark plug is removed. But, even if this is the case, the fact you have a damaged piston and cylinder are a major concern and will play a role in the fact whether you should precede further with any repairs.
 
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Old 05-22-07, 05:40 AM
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Puey61 - When I put the starter cord everything appears to move and behave as it should, except that the engine doesn't start. I do get the quick and fading put-put-put for about 4 or 5 cycles like you would a few times even when the blower was new...just doesn't catch and take off.

I'm still trying to carve out some time to try new gas - belt on the riding mower broke last night and I have to give that first priority...sure don't make things like they used to.
 
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Old 05-23-07, 05:48 PM
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Yay

And they all rejoiced....

I replaced the gas in the tank with a fresh mixture tonight, and after about 40 pulls, tweaking the throttle and choke, and playing with the pull-start pulling technique, finally got it to start and run.

I am quite confident that the number of pulls was necessary to clear out the old mixture. I also noticed that my pull-start technique seemed key. I had been previously pulling the cord and letting it go back in as quickly as the tension would take it. I found that pulling the cord all the way out and holding it there until the put-puts stopped seemed to allow the inner workings of the motor to continue spinning longer, and when I did this it sounded more likely to start. Indeed, only about 4 or 5 of this type of pull started the engine up.

Tanks to you folks for the tips...and for those who have similar issues...use a fresh gas mixture!

For those interested, I found a neat little tool at http://www.csgnetwork.com/oilfuelcalc.html that gives mixture ratios in an easy little calculator.
 
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Old 05-23-07, 06:35 PM
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Good news and good luck. On the calculator, this is a nice device but my recommendation is and always will be to use a quality brand synthetic oil and always mix it at the oil manufacturers recommended ratio. Typically, the oil package will spell out the ratio and required amount of oil to use per gallon of fuel.
 
 

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