blown 455 rancher

[muddstopper]

cousin brought me a 455 rancher he said wouldnt run. I pull the cord and it felt like zero compression. I could hold the cord and drop the saw and it would fall to the floor. so I checked the decom and it was good so I pulled the muffler. Muffler had gas pouring out of it, Its a good thing the saw wouldnt crank or it would have blown the muffler clean off.. Anyways, the piston and cyl looks as slick as a babies butt. So I am thinking just put a new ring in, then got to thinking, ring doesnt look stuck on piston, even tho there is plenty of carbon on the piston skirt. Why would the saw pass so much unburned fuel thru the cyl into the muffler. I havent checked the saw any further, but cant help but wonder why a saw with a slick cyl and piston have the compression value of a saw missing its spark plug.

 

[U&A]

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Sent while firmly grasping my redline lubed RAM [emoji231]

 

[undee70ss]

Im not up and up on Huskys, but there are many reasons why compression could be low, broken reed, loose cylinder, saw could have ingested something and be severally scored on the intake side ect...You just have to take it apart and find out why

 

[CausticUC]

Sounds like your carb float is way out or jet is missing/damaged.

Suppose the tank vent could be blocked and building up a huge amount of pressure to force fuel through the idle or choke circuit as well.

Lots of carb related reasons to dump fuel through an engine.

 

[Jasonrkba]

Sounds obvious but make sure the plug isn't loose.

 

[ATpro]

Or check and make sure there is not a hole in the top of the piston. A good reason to buy one of those USB cheap inspection cams with a light on the end that plugs into your cell phone. With one you can inspect the whole cylinder with ease. If you find a hole in the top of the piston it's probably from running the wrong spark plug. If so, when you pull the cylinder off to replace the piston be sure to wash the bottom end out real good to get any debris out that may have went through. The good news is if it's a blow through the saw would shut off and debris may not have damaged the lower end. Continuing the try to crank the saw and hitting the primer would flood the cylinder.

 

[m21bmr]

With the low compression but non-scored piston condition you describe, I suspect the ring is stuck. I haven't worked on many 455 ranchers, but two of the ones that I have worked on had a stuck ring, but no other damage.
As CausticUC mentioned above, it also sounds like there is a carb issue to investigate. Hopefully that will be something as simple as a bit of trash holding open the needle valve.

 

[cuinrearview]

My former BIL picked up a 460 rancher years back. Same symptoms, low comp but everything inside looked pristine. He pulled the jug and the ring was broken on the intake side. New piston kit and he was good to go.

 

[muddstopper]

I am sending the saw back unfixed.. My cousin doesnt want to spend any money fixing it and even tho I dont ever charge him for labor, I aint paying for parts. Personally, I cant see just replacing the ring in a clamshell saw. If it was mine, maybe. I would just add a ring to my next order and work on the saw when I had time. To tear the saw down you would be removing the crank and it may or not need seals, but at that point why not put them in. $6 here, $8 there then possibly a carb kit and the $25 ring the saw shop just priced to me, pretty soon its time to rethink even fixing a saw he hasnt bought yet. Add fixing to the price of buying the saw, it just doesnt add up.

 

[cuinrearview]

I am sending the saw back unfixed.. My cousin doesnt want to spend any money fixing it and even tho I dont ever charge him for labor, I aint paying for parts. Personally, I cant see just replacing the ring in a clamshell saw. If it was mine, maybe. I would just add a ring to my next order and work on the saw when I had time. To tear the saw down you would be removing the crank and it may or not need seals, but at that point why not put them in. $6 here, $8 there then possibly a carb kit and the $25 ring the saw shop just priced to me, pretty soon its time to rethink even fixing a saw he hasnt bought yet. Add fixing to the price of buying the saw, it just doesnt add up.

Imagine the bill for the saws, clamshell or other, at $80/hr in the shop...