555 no fuel issue

[huskyhansen]

Ok just picked up this 555 autotune for 100 bucks it's in great shape but wouldn' start. It has spark. new plug, air filter/fuel filter are good and seems to have decent compression. Pulled like crazy with choke on and off. Held it wide open and not so much as a hickup. Pulled plug and its dry so i dont think it's getting any fuel. What now? Primer bulb seems to be working. Thinking the autotune took a crap?

 

[Andyshine77]

Ok just picked up this 555 autotune for 100 bucks it's in great shape but wouldn' start. It has spark. new plug, air filter/fuel filter are good and seems to have decent compression. Pulled like crazy with choke on and off. Held it wide open and not so much as a hickup. Pulled plug and its dry so i dont think it's getting any fuel. What now? Primer bulb seems to be working. Thinking the autotune took a crap?

Unlikely the AT took a dump. Diagnosis it like any other. First shoot a little fuel in it and see if it fires. Take the carburetor off, clean it out and inspect/replace the diaphragms. I bet the diaphragms are, stiff or the metering lever is stuck shut.

 

[huskyhansen]

The dude told me he dumped fuel in it and still no luck but I haven't tried that. Just a splash?

 

[huskyhansen]

I can't find a rebuild kit. Just the complete carb assembly.

 

[merc_man]

Pull muffler and check the piston. Probly scored and no compression.

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[huskyhansen]

Dang that was a good call. Looks like something hit the top of the piston.

 

[huskyhansen]

 

[merc_man]

Time to do a little digging and see what went wrong.

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[huskyhansen]

I don't get how that could even happen. Trying to find a dang allen that can reach probably have to buy a new one tomorrow.

 

[huskyhansen]

 

[huskyhansen]

Looks like piston kissed exhaust port? How the neck. I personally know both owners and saw was hardly used. I guess I need a full rebuild? Major bummer.

 

[huskyhansen]

Will a 560/562 cylinder and piston work?

 

[Andyshine77]

How's the top of the piston look? something forging did that, maybe a chunk of carbon, needle bearing or ring pin. I see a lot of carbon for a low use saw. The cylinder doesn't look too bad from what I can see. If everything checks out, smooth out the top of the port, put a new piston in it and see if she runs.

 

[Andyshine77]

Will a 560/562 cylinder and piston work?

Yes it should, not sure about the carb and AT stuff. It's been done, but that was some time ago.

 

[huskyhansen]

 

[grizz55chev]

Someone used a screwdriver for a pistonstop.

 

[huskyhansen]

I know the two owners. First guy bought it new obviously and wanted something bigger. Second guy only changed the plug. I don' understand what damaged it.

 

[Andyshine77]

Someone used a screwdriver for a pistonstop.

That's exactly what I was thinking before, now it's fact!

 

[Andyshine77]

I know the two owners. First guy bought it new obviously and wanted something bigger. Second guy only changed the plug. I don' understand what damaged it.

Screwdriver, I bet he was using it as a piston stop.

 

[Andyshine77]

That's why the cylinder is pretty clean it never ran again.