bottom-end seizure? (P&C are still mint)

[CamMann]

Any thoughts on non P&C related seizures? Can crank-bearings seize a saw?

Friend brought me a fairly new, seized saw he had come across, with very little info about it. First unusual thing i found was that it had something other than fuel in the tank, seemed like water. Anyway, took off recoil, sparkplug, and muffler. Had a good view of the cylinder and it seemed fine so far. I sprayed penetrating oil in, and put back & forth pressure on crank-bolt. I could move the piston up & down like 1/8". Felt like the resistance wasn't in the P&C, but elsewhere. kept at it and slowly got enough rotation to spray penetrating oil into the crankcase via piston's transfers. Little more lubed back & forth, and the everything moved quite freely by hand. Everything seemed normal at this point, but there had to be a reason it was seized. Decided to investigate deeper, pulled off the cylinder. P&C are mint!! crank-case is clean as a whistle. wrist-pin & connecting rod bearings feel normal. crank bearings have no unusual play, they move freely, but one does seem slightly noisier than normal. So, my best guess at this point is crank-bearing issues, but idk. I've not come across a bottom-end seizure before though. Any thoughts/input would be much appreciated.

 

[RED-85-Z51]

Yes they can, either from corrosion, lack of lube, cage failure, a number of possibilities.

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[J D]

I'd fill the case up with mix, turn it over a bunch then dump mix into a clean container & inspect for debris... Repeat a few times & see what comes out & if it feels "bindie" at all throughout

 

[pioneerguy600]

If it was water and it likely was then the balls will be micro pitted, the race often will withstand more moisture without rusting but either way the bearing will slowly self destruct. Just depends on how long you want the saw to run after freeing the crank up.

 

[SteveSr]

Friend brought me a fairly new, seized saw he had come across, with very little info about it. First unusual thing i found was that it had something other than fuel in the tank, seemed like water.

Water, gas, and oil don't mix. Definitely sounds like water ingestion. New crank bearings and very close inspection of both rod bearings or just a new crank. I suspect that you will find damage when you remove the crank bearings.

 

[RED-85-Z51]

Reminds me of an Echo 4400 i had come in years ago, it was under water during Hurricane Ivan and was locked. Guy was desperate...needed to cut wood to clean up debris, i soaked it in oil, hit the piston with a dowel on top and turned the crank...it freed up but was gritty. Flushed it out as best i could...it rolled over okay. Started up but the bearings roared over everything else. I told him, no idea how long it will last but it runs. 4 or 5 years later he was stll using it..loud as ever....at idle it sounded like a skateboard on asphalt.

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[farmguywithasaw]

Sounds like new bearings would be you best bet crank is probably fine

 

[CamMann]

Lots of great input; much appreciated everyone! Always a pleasure to learn from you all. After spraying the bearings with oil and it sitting overnight, there did seem to be a rust-colored sediment that came out & pooled below them. So, the likely culprit was bearing corrosion from the water ingestion. Just ordered bearings, seals, gaskets, etc. I'll take a closer look at the crank too. Thanks again!!

 

[pioneerguy600]

Reminds me of an Echo 4400 i had come in years ago, it was under water during Hurricane Ivan and was locked. Guy was desperate...needed to cut wood to clean up debris, i soaked it in oil, hit the piston with a dowel on top and turned the crank...it freed up but was gritty. Flushed it out as best i could...it rolled over okay. Started up but the bearings roared over everything else. I told him, no idea how long it will last but it runs. 4 or 5 years later he was stll using it..loud as ever....at idle it sounded like a skateboard on asphalt.

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I have a SD 116 that was given to me after it sat full of water for a month or more, it did not quite seize but after dumping the water out it was slightly stuck but easily broke free on the first pull over with the recoil. I drained every tank, rebuilt the carb and got it running with little effort but the bearing noise sounds just like you say, skateboard on asphalt. I keep it as a parts saw, just filled it with new 10W30 so the main parts would still be usable in the future.

 

[CamMann]

Update: Took out the old bearings & they were definitely rough with rust. New bearing, seals, gaskets, & carb-kit came in. This saw runs & sounds excellent now. Just wanted to say thanks again everyone! Buddy hasn't picked it up yet, but I'm sure he'll be thrilled when he does. much appreciated!