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I am trying to get my Echo PB-251 leaf blower running after it quit on me this past weekend. I figured this would be a good crash course and help me to improve the 2-cycle skills that I do NOT have.

Air, spark, fuel - that simple, right? Not for me. I have done the following:

1) confirmed that I have a blue spark on the plug. Even though that checked out, I installed a new plug.
2) checked the air filter. I replaced it last year as part of a tune up kit. Looks good and I tried to starting it with this removed. No luck.
3) spark arrestor - I hear these can get clogged and cause symptoms so I removed this to clean it but it was already clean from the last time that I did this.
4) fuel? Not sure so I removed the fuel filter which was also replaced last year. I do get gas into the primer bulb so I don't think there is a problem with the fuel line. I also tried to eliminate fuel as the issue by putting some directly in the cylinder and trying to start it. No luck.
5) I replaced the carburetor just in case it is the fuel and because the tech at the local mower repair store said that this must be the problem due to my summary above. No change after installing a brand new carb.
5) compression - I used my harbor freight gauge and it showed 70 PSI. I know this sounds low and my gauge might also be suspect. I also looked at the piston and ring through the muffler/exhaust and iI do not see any evidence of scoring or damage. This is limited as far as what I can see. I did add some 2 stroke oil directly into the cylinder since I heard this can help if the compression is too low and sure it enough, it tried to start and created smoke and a small firing bang.

This is not about the money but about understanding this 2 cycle and making it run.

Can you help with some next steps and recommendations on what to check?

Quick update - I used my compression tester to test the compression on the new Stihl blower that I have and that measures.... 70 PSI. That tells me that this gauge is off and it tells me that compression was not the problem with my Echo which is now in pieces.

I hope to get some advice that leads me to want to try to reassemble the echo and win this challenge.

Thank you

Ok it sounds like you have diagnosed your problem already but I would do a little more testing to make sure. First get new compression tester and test compression. Add small amount of oil to cylinder and test again. If compression goes up rings are bad.

4x15mph said:

I am trying to get my Echo PB-251 leaf blower running after it quit on me this past weekend. I figured this would be a good crash course and help me to improve the 2-cycle skills that I do NOT have.

Air, spark, fuel - that simple, right? Not for me. I have done the following:

1) confirmed that I have a blue spark on the plug. Even though that checked out, I installed a new plug.
2) checked the air filter. I replaced it last year as part of a tune up kit. Looks good and I tried to starting it with this removed. No luck.
3) spark arrestor - I hear these can get clogged and cause symptoms so I removed this to clean it but it was already clean from the last time that I did this.
4) fuel? Not sure so I removed the fuel filter which was also replaced last year. I do get gas into the primer bulb so I don't think there is a problem with the fuel line. I also tried to eliminate fuel as the issue by putting some directly in the cylinder and trying to start it. No luck.
5) I replaced the carburetor just in case it is the fuel and because the tech at the local mower repair store said that this must be the problem due to my summary above. No change after installing a brand new carb.
5) compression - I used my harbor freight gauge and it showed 70 PSI. I know this sounds low and my gauge might also be suspect. I also looked at the piston and ring through the muffler/exhaust and iI do not see any evidence of scoring or damage. This is limited as far as what I can see. I did add some 2 stroke oil directly into the cylinder since I heard this can help if the compression is too low and sure it enough, it tried to start and created smoke and a small firing bang.

This is not about the money but about understanding this 2 cycle and making it run.

Can you help with some next steps and recommendations on what to check?

Click to expand...

I had a problem with my Ryobi blower it also showed 70 lbs pressure I disassembled the piston and found the piston rings were rusted to the piston,I replaced the assembly (Ryobi doesn't sell rings) My pressure was now at 140 it started on 2 pulls I had other problems at fast idle due to carb. Adjustments but now it runs fine.

Some ideas...

• First of all primary compression is much more important on a 2-stroke than top-end compression. So your pressure readings don't really help.
• Pumping fuel only means fuel is getting to the carb.... not into or thru the carb.
• Are you using ethanol fuel ? Has the unit run with ethanol with this new carb ? And how long since you last ran it ?
• I bet you are NOT seeing any wetness on the new plug. The fuel jets for these tiny engines are TINY and they bock easily. Take the H screw and turn it in slowly until it touches. Remember that setting. Now turn the screw back out and add 1/2 turn. You should start to see wetness.

Hope this helps.

4x15mph said:

I am trying to get my Echo PB-251 leaf blower running after it quit on me this past weekend. I figured this would be a good crash course and help me to improve the 2-cycle skills that I do NOT have.

Air, spark, fuel - that simple, right? Not for me. I have done the following:

1) confirmed that I have a blue spark on the plug. Even though that checked out, I installed a new plug.
2) checked the air filter. I replaced it last year as part of a tune up kit. Looks good and I tried to starting it with this removed. No luck.
3) spark arrestor - I hear these can get clogged and cause symptoms so I removed this to clean it but it was already clean from the last time that I did this.
4) fuel? Not sure so I removed the fuel filter which was also replaced last year. I do get gas into the primer bulb so I don't think there is a problem with the fuel line. I also tried to eliminate fuel as the issue by putting some directly in the cylinder and trying to start it. No luck.
5) I replaced the carburetor just in case it is the fuel and because the tech at the local mower repair store said that this must be the problem due to my summary above. No change after installing a brand new carb.
5) compression - I used my harbor freight gauge and it showed 70 PSI. I know this sounds low and my gauge might also be suspect. I also looked at the piston and ring through the muffler/exhaust and iI do not see any evidence of scoring or damage. This is limited as far as what I can see. I did add some 2 stroke oil directly into the cylinder since I heard this can help if the compression is too low and sure it enough, it tried to start and created smoke and a small firing bang.

This is not about the money but about understanding this 2 cycle and making it run.

Can you help with some next steps and recommendations on what to check?

Click to expand...

Echo sells a piston rebuild kit,check YouTube for instructions.