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Manage My Life

So frustrated with Craftsman 25cc Gas Blower not starting - model #358.797170 - 2 Cycle

I have made another post on this piece of machine and starting issues, but am writing a new one to summarize all I have tried to do to get it to start/run. I hear many say Craftsman gas tools aren't made like they used to and are trouble now. I tried to not believe it, but honestly I'm starting to agree. I got this gas leaf blower used cheap and tried to fix it. I would've left it where it was if I knew how much trouble it was. :(


This seems ridiculous that it won't run. Here's what I have done to date. I'm out of ideas/options.


- Changed spark plug - uses CJ-6Y


- Rinsed/cleaned foam air filter - looks fine


- Had to tighten engine block as two main bolts seemed a bit loose probably causing compression issues. Totally fine now. I'm not sure how to check pistons/gaskets, but...


- Completely cleaned spark plug arrestor screen - it was completely caked over with 0 clearance - used wire brush - now looks like new


- Total rebuild of Zama Carbeurator - model # C1Q - W11C 36A. Bought new rebuild kit (RB-47) and replaced all gaskets. Did carb cleaning too.


- Installed new fuel lines. Installed new fuel filter - I did have to enlarge the gas line hole in the tank slightly that accepts the fuel filter as I couldn't find replacement line that matched the old. It's now the same diameter as the fuel line that goes to the inlet in the tank. Lines are tight - no leakage out of the thank.


I checked compression with a tester. Three pulls showed 110, 130, 150...I thought 90+ compression is enough to start.


I used a spark tester. Lit up just fine. If I put a little starter spray in the carb, it'll turn over, but die out.


When I push the primer bulb, it fills up with fuel easily and depresses just fine.


I have no idea how to adjust H/L settings on carb.


I mean geez....what else is left? I won't put anymore $$$$ into it as it's not worth it. It's not that good of a unit. :) However, I did invest some so I hate getting nothing out of my investment to date.


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Craftsman , Gas Blowers , Kenmore PRO Appliances
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21 Answers from these members:
Stephen Viccari
All you need to do is replace the carb. No matter how many times you try to clean and/ or rebuild these carbs there is no way to unclog them. Believe me I have tried soaking in carb cleaner, used mechanic in a bottle ( which btw is great if the carb is dirty amd is hard to start. Once a little dirt gets in the carb there is no getting it out.I tryed completely disassembling the carb, replaced the needle valve asy, screen, jet and all other parts that come in the rebuild kit. For about $25 you can buy a new carb and it will start and run great
by Stephen Viccari
July 2nd
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Jim Purintun
Where are the answers?????
by Jim Purintun
May 7th
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Mark T
Bob and Joe,






The cylinder bolts should be torqued to 90 inch pounds. If they came loose, make sure the vibration did not open the bolt holes bigger. If they come loose again, I recommend putting some high temp loctite on the bolts before putting it back together. I hope this is helpful.



Please let me know if you need further assistance.



Have a great day!!






Mark
by Mark T Earned 1,607 community points in Craftsman
June 15th, 2012
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Bob Ryckman
Yes, that is what I did and she runs great now.
by Bob Ryckman
June 14th, 2012
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Manage My Life
Bob, just tighten the screws tight and that will be good, just make sure the head is not moving
by Manage My Life
June 14th, 2012
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Manage My Life
I had the same problem with the same gasoline powered blower model 358.797170, and I found what the problem is. The head inside the housing gets loose from vibration and the timing is off. There are two hex head screws that needs to be tighten. When that is done it should start right up.
by Manage My Life
June 14th, 2012
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Bob Ryckman
Yes, Joe you are correct the cylinder head was loose on my blower too. Although I don't know how much to torque the bolts to.

br
by Bob Ryckman
June 14th, 2012
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Manage My Life
I had the same problem with the same gasoline powered blower model 358.797170, and I found what the problem is. The head inside the housing gets loose from vibration and the timing is off. There are two hex head screws that needs to be tighten. When that is done it should start right up.
by Manage My Life
June 14th, 2012
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Manage My Life
I had the same problem with the same gasoline powered blower model 358.797170, and I found what the problem is. The head inside the housing gets loose from vibration and the timing is off. There are two hex head screws that needs to be tighten. When that is done it should start right up.
by Manage My Life
June 14th, 2012
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Mark T
Hi, I am Mark and I will be helping you today. Wade has left the company to move back home to Louisiana. If you have replaced the carburetor and the fuel lines are not cracked, I recommend swapping the fuel lines on the carburetor. If the lines were reversed, the engine will not get fuel. Once you have the lines switched check the operation. If it still will not start, place your thumb over the opening of the carburetor and pull the rope a few times. You should feel a vacuum when pilling the rope. If you do not have the vacuum, there is a problem internally in the engine. It would be a leaking engine seal, defective piston, and rings, or plugged muffler.

I hope this is helpful. Please let me know if you need further assistance.
by Mark T Earned 1,607 community points in Craftsman
April 5th, 2012
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Bob Ryckman
Hi Wade, did this problem get resolved? I have a Blower Vac 358797170 I purchased in 2003, it has always started on the first or second pull until last summer. Now it will not start. I replaced the spark plug (gapped correctly) and carborator with new parts from parts direct. still no luck. The primer is getting fuel, but the fuel is not getting thru the carborator to the cylinder (I replaced the carb thinking maybe it had a bad diaphram or something, but the new one has the same problem) the fuel filter appears to be working to me, I pulled out the line and filter and pushed the primer and fuel moves thru it and the excess goes back into the tank (or all of it in my case). If i stick a shot of carb spray into the carborator it will fire and run but as soon as the spray is gone it dies, and still will not start. I have cleaned the fuel cap with carb spay, but still will not fire. Other thoughts?
by Bob Ryckman
April 4th, 2012
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Manage My Life
If it's not the welch plug then it's not removable, without destroying something. The drawing is not real clear as it only show the welch plug there. For me, I hate working on these little carburetors and in most cases I just replace them when it's feasible.

Working on a carburetor is certainly the right way to learn how to work on them. You may look around the local want ads or even on Ebay and find a used carburetor for a mower or tractor for cheap and then go through it. Once you work on a bigger one (where you can kind of see stuff better) the smaller ones start to make more sense. but the smaller ones are still a pain in most cases.
by Manage My Life
July 24th, 2011
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Manage My Life
Now learning to tune a carb properly seems like a whole other battle to undertake sometime! :) I really want to learn more on this topic, but it's obviously impossible with a carb that doesn't work right to begin with.
by Manage My Life
July 23rd, 2011
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Manage My Life
Wade at this point, I agree fully. Whoever owned this machine obviously did zero maintenance. I've already dropped about $35 into this w/the purchase price. I guess either I consider it a total loss or buy the $25 carb and get a usable machine (I really hope). If it works, I could probably sell it for $40-$50 as the rest of it is in very good condition. Or sell it for 'parts' and tell someone the carb is bad and needs to be replaced.

Either way, it sucks I couldn't fix it easily. BUT, I learned a lot about carbs I never knew before. I now most likely have the ability to make simple carb repairs on units not as far gone as this carb. :) That will save me money in the long-run which is cool.

I don't believe that circled area is the Welch Plug. I already replaced it. That was under the metering arm lever and more oval in shape (flat piece of metal). Not something I would touch again. I'm pretty sure the circled brass piece is the check valve nozzle assembly. BUT, I'm no expert. lol. Just following Zama's manuals.
by Manage My Life
July 23rd, 2011
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Manage My Life
I'm pretty sure both of those screws are damaged. Every drawing I can find of them shows them as having a point and not rounded on the tip like that. I've never seen an air screw rounded on the end either. In your picture the brass plug is a welch plug. My first link to this post is a PDF file for the parts breakdown of your carburetor.

I know this thing is frustrating you, my recommendation is to spend about $26 and replace the carburetor with replacement number 530071775. I know you mentioned you don't want to put more money in the blower (and I don't blame you), but playing around with these little carburetors can be a nightmare at times. Not knowing the history of the machine certainly doesn't help because you don't know how it was treated.
by Manage My Life
July 23rd, 2011
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Manage My Life
Last comment - I have tried several settings for the metering level too. I used a straight-edge and it's flat with the carb body as mentioned in the Zama user guide. I still struggle with how to measure this process accurately. I have a Zama 'Z tool' coming in the mail. Based on the way things are running, I doubt that's the issue though.
by Manage My Life
July 22nd, 2011
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Manage My Life
I'm also wondering if the inlet check valve on the carb could be scrapped. This is non-replaceable. That main check nozzle valve can be replaced for $4-$5 I believe IF one can find parts. I don't think this is a possible reason why my unit would not hit full power on full throttle.
by Manage My Life
July 22nd, 2011
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Manage My Life
Wade, this machine is just a nightmare. :)

Here's the latest update. I figured out the carb adapter assembly was loose on the unit. I tightened the two allen bolts and it's totally secure now. Once I did that, I can get the blower to start now on the first or second pull max. :) That's good news.

Now the bad news. I cannot get the blower to generate any power in full throttle. The power seems like 20% of what it was before. When I try to take it down to medium or low throttle, the engine dies.

I'm hoping the screws weren't forced in too hard as you warned (should've read before). I'm guessing this could've happened as I'm using that makeshift tool (wire crimp connector) to adjust them. I have put them all the way set in and backed off 1 to 1.5 turns as mentioned. Turning the H screw counter-clockwise results in no pick-up of power. Something is wrong.

If the carb choke is wide open and the engine is running, is it normal to have a fine mist spray of fuel/air shooting out? This is without the air filter on because I'm trying to adjust the mixture screws while the engine is performing.

It's nice it starts now, but I don't understand the complete loss of throttle power as the few times it started before, that aspect was fine. It never ends!

I looked through the Zama carb service guide at all reasons why the unit could have low power at full throttle. Most of the possibilities don't seem like an issue with my blower/carb.

Would damaged mixture screws cause this issue? What about a damaged main check nozzle valve? I have attached two pictures. I'm wondering if you can tell from the picture of the screws if there is any damage?

Of course I don't know, but I would assume the piston/cylinders are OK if the unit was able to run full throttle before without bogging down. I don't see any scoring on the piston. I wonder if a loose engine seal could cause this, but would the unit even start if this was a problem?
by Manage My Life
July 22nd, 2011
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Manage My Life
It does sound like you've addressed almost everything on this unit.

Are you sure the fuel lines are connected correctly? If there is any doubt, reverse them and see what happens. On the carburetor, turn the air adjustment screws all the way in until they seat. Do not turn them with any force once they set as it will damage the screws. Once they're screwed in all the way, back each one of them out 1 full turn and adjust from there as needed.

The compression should be fine as around 100PSI is pretty stand on a machine with some hours of run time.

Because the machine wants to fire up when you spray down into the plug hole, I'd say our main issue is going to be carburetor/fuel related. Having put a rebuild kit in place and cleaned the carb I don't know that the carburetor will be the issue unless it's just a matter of getting it adjusted correctly. If you have some carb cleaner you can use it as starting fluid. Spray it down the throat of the carburetor and see if you can get it to run long enough to get some basic carburetor adjustments done to where it will start.

Let me know where you stand with this.
by Manage My Life
July 21st, 2011
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Manage My Life
Of course I forgot to mention the obvious. I put new gas/oil in it (40:1 mix) as instructed per manufacturer.
by Manage My Life
July 19th, 2011
Answered in 7 minutes
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Manage My Life
It seems like you need some special tool to adjust High and Low carb speed settings. I assume they are pre-set at the factory and should be OK. Would this hinder starting? Seems doubtful. I would think it just wouldn't run as well.

I even replaced small filter screen on carb and put in new inlet and needle. The setting seems similar to before.
by Manage My Life
July 19th, 2011
Answered in 4 minutes
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