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Craftsman 25cc Gas Leaf Blower won't start


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06-03-16, 09:36 PM   #1  
Craftsman 25cc Gas Leaf Blower won't start

History: Started and ran several times this spring already. Fresh gas to start the year. It usually started in 2-3 pulls and once started, I would need to keep reving it to keep it going. If I let it idle, it would die and if I just floored the throttle it would die. It took a long time (longer than I remember previously) to get to a point that it would run at either full throttle or at idle without dying. Also, it seemed to have just a little less power than before but I may have been imagining this. Anyway, I have used it several times this spring as I said with not much trouble starting it. Starting in early April, I used it to clear all the sand off the road in front of our house after the snow plows load it up over the winter. That was a good hour of running time. Then I have used it to blow leaves from around the house. A good half hour straight. Then a few times to clean drive and deck after mowing the lawn for just 5 or 10 minutes each time (3 or 4 times). Today, I wanted to blow some leaves that had collected under a trailer and it tried to start on the second pull but died. Subsequent pulls showed no sign of life. I let it set for an hour in the shade and tried again, nothing. I tried several hours later and nothing. I pulled the plug and plenty of gas on it. The plug looks good. I tested for spark and have good blue spark. I pulled the plastic side plate off and the back piece covering the air filter. I cleaned the air filter and put it back in and tried to start it, but nothing. I have got rid of the gas, emptied the gas tank and refilled with fresh 40:1 premium (no ethanol) gas. Still no love.
You guys helped me out a week ago on my Craftsman push mower but now that I have that running, the leaf blower is giving me fits. Craftsman is making my life difficult this Summer.
If anyone has any other suggestions, let me know. Easy and cheap fixes first please. Oh, when I pulled off the plastic side plate, this part was full of nasty oily gunk as shown in the photo. I don't think it would cause the problems I am having, but maybe it is a symptom. It is called the "Crankcase Plug Assembly".
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Here is the data plate on the blower. Model # 358.794774
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Here is the shroud that I removed covering the "Crankcase Plug Assembly" above.
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cheese's Avatar
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06-04-16, 01:12 AM   #2  
The symptoms you describe of how it was running before it quit makes it sound like it was running lean. Combine that with the fact that you continued to use it probably means the piston and cylinder walls are scored. Do you have a compression gauge? You could pull the muffler off and have a look into the cylinder to see the piston and cylinder wall but I think you cooked it. Might be time for a new one, have a look to be sure.


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God bless!

 
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06-04-16, 07:58 AM   #3  
OK, I will pull the muffler this afternoon and look. I will report back.
Thanks

 
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06-04-16, 10:22 AM   #4  
Ok, strange. I pulled the muffler today and it looked pretty gunky in there as well up to the cylinder. I could see the piston and ring and from what I could tell, it looked OK. I was going to pull the head off the motor and I got out the one screw but the access hole for the second screw was too narrow to get my 5/16 hex bit down there. Not sure why it is so much narrower than the other hole. Does any one know if it is the same 5/16 bolt as the other one. If so, I will get a long allen wrench or other tool with that tip that I can get down there.

Also, the strange thing is, once I pulled the muffler, I decided to try to start it again. I put the switch in the Start position and nothing. I moved it back to the Run position and it sounded like it was trying to do something. It was hard to tell with the muffler off. But, I decided to hold the throttle open a bit and try it and after a couple pulls it tried to start. I had another almost start and then it fired and I goosed the throttle for about thirty seconds and it was seemingly running fine, even at idle. And it was running well at full throttle as well.
Two possible thoughts. When i removed and reinstalled the head bolt, maybe it was loose. Second, maybe it just took a bit to get the new gas through the system and into the cylinder.

But anyway, the head bolt didn't seem very tight at all when I took it out and am wondering if they both were loose. So, I want to remove them both and put some loc-tite on them and put them back in. I have seen in many forums where loose head bolts were an issue on these things. So, let me know if the second head bolt is also a 5/16" hex.

 
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06-04-16, 12:46 PM   #5  
Loose head bolts is a common issue on these. You might be lucky and not have any damage from running lean. I think both bolts take the same size allen wrench if I recall correctly.


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

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06-04-16, 12:56 PM   #6  
Went out and bought a new allen wrench set...why is it that I seem to have are metric....or they are too short. Anyway, bought a set and it takes a 3/16" wrench. I went to loosen the other head bolt and it was tight. I should have just left it, but I figured if I was going to loc-tite one, I would do them both. Besides, that is what I bought the allen wrench set and loc-tite for. So, it was tough to get it all the way backed out of the threads and when I went to to shake it out after it was free of the threads, it must have dropped out when I wasn't looking. It is gone and I went through the trouble of scouring the garage floor all around my work bench and even cleaned off my work bench but nothing. I simply lost it. I can't hear it inside the blower housing when I shake it and it doesn't rattle when I pull the starter cord, so I don't think it is in the blower. I broke down and ordered one of Searspartsdirect.com. Over $7 but what are you going to do?
Anyway, wish me luck, it should be here in about ten days. I will be really disappointed if it doesn't start and run good after this.

 
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06-05-16, 07:33 AM   #7  
If it runs with the muffler off but not on, check your spark arrestor. On the muffler there is a small plate usually held on by one or more phillips screws, under it is a screen that if it becomes clogged will cause problems.


Just needs a bigger hammer
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06-05-16, 08:52 AM   #8  
BFHFixit: I need a little more information. What exactly is the "spark arrestor". Is it part of the muffler itself?
Can you see it in this photo (ignore the yellow circle).

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06-05-16, 09:25 AM   #9  
It would be in the assemblage: Engine/exhaust port/spark arrestor/muffler. Not all engines have them, but a leaf blower should.

 
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06-05-16, 09:43 AM   #10  
So, what you are saying is that it would part of the muffler itself? i don't think there is anyway way to disassemble the muffler so it would be a new muffler?

 
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06-05-16, 01:22 PM   #11  
You mean to replace the muffler? No, the muffler itself really doesn't plug, but the spark arrestor on a two stroke has a habit of clogging with carbon since it has smaller openings to trap sparks. You may not have one.

The muffler you would replace for rust outs and stuff like that. If yours is intact just clean it up and rinse it with soapy water when you're done.

 
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06-05-16, 03:47 PM   #12  
marbobj, thanks for your help, but I guess I am a little confused. Well, I know I am. Is the spark arrestor part of the muffler or not? If not, where do I find it? If so, how do I check it and what would I look for? Also, how do I "clean" the muffler with soapy water? Just soak it? It doesnt come apart and the outside of it is not dirty or corroded as shown in the photo below.

 
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06-05-16, 04:58 PM   #13  
I looked it up at Sears. YOu don't have a spark arrestor. You just have the muffler and a heat shield. You cannot disassemble the muffler and normally you don't have to wash them out.

However, if you would like to clean it, you would typically rinse it with a solvent like carb or brake cleaner. If you did so, the reason you would need to rinse it out with soapy water is to get rid of the flammable vapors in the muffler. Those could ignite and although they often have that type of thing go through them and backfire, etc., washing it out with the soapy solution is just a precaution.

That muffler you have doesn't look like it has had any use and probably isn't plugged with carbon, but it could have maybe a mud dauber nest or something like that in it. You can tell if it's plugged badly just by blowing through it.

 
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06-05-16, 11:55 PM   #14  
Thanks,
I just hope that once I get the new head bolt and put it in, the dumb thing starts and runs like it is supposed to. If not, I will pull the muffler off again and check it out. I will remember to post back with the outcome.

 
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06-06-16, 04:29 AM   #15  
The head bolt could fix the problem - depends on what it was causing in terms of compression or engine vacuum/air flow loss. A two stroke is a little fussier than a four stroke in that area since the crankcase is part of the feed to the intake of the combustion chamber. Which brings us to that gunked up crankcase plug.

That thing is an assembly doorway to stick the crank in the crankcase. There's a lot of different designs for that type of thing, but the only important consideration on yours is the crankcase is on a two stroke and it has to be sealed to air. That plug has to be air tight and if the gunk is coming out air could very well be getting in. It needs to be pulled and cleaned and resealed . It seals with just an "O" ring on some models that looks like what you have. You can replace it for about $3.00 - not expensive.

In looking farther on the spark arrestor for those things. It looks like there is a kit available and that may be OEM on some models. The IPL for yours shows none.

Your blower may start with the muffler off if there is a weak link in the air flow of the engine since it will be a slight restriction on the very end. That weak link could be something in the head sealing with the head bolt or it could be the crankcase plug leaking or the crank seal on the other end of the crank leaking air.

 
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06-09-16, 03:17 PM   #16  
Just wanted to followup with an update. I received the new head bolt this afternoon, got it installed and after some aggravation got the thing started and purring like a loud kitten. After everything, I am going to put the ultimate blame on bad gas as the reason for the blower not starting to begin with. I suppose it could have something to do with me disassembling it and messing with it, but I think, in the end, it was me replacing the gas that was in it that got it running again. In the mean time, I learned a bit more about leaf blowers and how they work. The biggest thing I learned however is that they are a PITA to work on.

https://www.youtube.com/watch?v=UjEF8U7swq8

 
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06-09-16, 03:29 PM   #17  
The biggest thing I learned however is that they are a PITA to work on.


Any time you see equipment that small that requires more steps to start than it does an Aircraft....


Just needs a bigger hammer
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