siezed chainsaw

[carterbeauford]

Siezed up dad's Jonsered 2065 Turbo yesterday. It wasn't working hard but was making smoke out the starter cover. Oil mix was 50/1. I think the crank seals are worn allowing air into the mix and a lean condition. I freed up the piston with PB blaster and a bronze punch. Seems like it has compression, waiting on a new spark plug to see if it will start. Debating repair vs replace at this point, I can get a comparable Stihl for $500. Told him I'd take care of it. Trying to convince him to replace. He is very attached to that saw, probably has 1000 hours on it.

 

[jabberwoki]

It`s your dads call. Replacing a piston and head on saws is really easy, just depends on replacement parts costs.

 

[Showkey]

Also depends on the crank bearings and rod bearing............loose rod and new piston, rings and cylinder is bad combo and bad investment. Not mention the crank seal already a concern.

 

[Steve_P]

I don't think I've ever seen failed bearings when a two cycle locks up; but the piston, rings, cylinder all get scored and need replacement.

 

[Indexmill]

Replacing crank seals can be real work. Especially on the older magnesium saws.

So do a leak test to be sure before doing the top end.

 

[bpjr]

I'd do whatever your dad wants but at that many hours I'd probably buy a new saw of his choice and rebuild the old one for a backup.

 

[Davefr]

Bottom end work can get expensive (OEM parts), labor intensive and often requires specialized tools. I'd think twice about going that direction.

At 1000 hours that saw has paid for itself. I'd say a new saw is the best bet. He'll come around.

 

[Dumber than lumber]

I'd do whatever your dad wants but at that many hours I'd probably buy a new saw of his choice and rebuild the old one for a backup.

^ ^ ^ ^ ^ This makes a lot of sense to me.

 

[Bigblockyeti]

$500 for a 1000 hour saw made by any manufacturer = hard pass.

 

[MrAmmons]

Please do not attempt to start the saw without at least pulling the top end and assessing the damage. If it was lean seized most likely there will be pieces of molten material in there, no need to make it worse.

Crank seals are a possibility, but I'd start cheap and clean or get a new air filter, check the intake boot for cracks, obviously replace the piston and rings, use scotch brite or a hone to clean up the cylinder, flush the bottom end real well. Reassemble and run it for a few years more.

 

[MrAmmons]

Additional information

Piston kit:
https://www.ebay.com/itm/Meteor-pis...898?_trksid=p2349526.m4383.l4275.c10#viTabs_0

Wrist Pin Bearing:
https://www.ereplacementparts.com/support-bushing-p-2620157.html

Parts List:
https://www.ereplacementparts.com/jonsered-2065-199702-chain-saw-parts-c-511202_511205_511839.html

 

[carterbeauford]

Bought him a brand new 20" MS271 and he wants the Jonsered back. I'll rebuild top end over the winter as much as he uses it anymore.

 

[bob15]

Bought him a brand new 20" MS271 and he wants the Jonsered back. I'll rebuild top end over the winter as much as he uses it anymore.

I can see where he is coming from.

If someone seized my PM700, I would want it repaired, not replaced. Call it sentimental, but it was my first (of only 2) brand new saws I ever owned....the remaining dozens were all second/third/forth hand saws. If it was broken by someone, I would expect that person to fulfill my wish and get it fixed, not replaced.

 

[Firebrick43]

Most of the time when a 2 stroke lean seizes there is transfer of aluminum onto the cylinder walls. Most of the time the cylinder wall itself is not damaged but many get damaged while the mech tries to mechanical means of removing the aluminum.

The best way of removal is muriatic acid applied with a qtip to the specific area. In less than a half hour the aluminum transfer will have been eaten away, clean with baking soda and water, and put a new piston in and in your case crank seals.

The nikosil or chrome will not be damaged by the acid, of their is damage I was caused by the seizure. I have only seen 1 out of a dozen that this was the case.

Don’t use or store the muriatic acid around anything as even the fumes are pretty wicked.

 

[carterbeauford]

I totally get the sentimentality of the saw, it's a badass old saw.

 

[finn]

Listen to Firebrick.

Pull the muffler to catch a look at the piston skirt.


Pressure check the case and replace the seals on a saw that old, or any saw with a suspected lean seizure.

 

[carterbeauford]

Replaced piston, cylinder, seals and muffler with a kit off Ebay. $40 and 2 hours of labor. stock was 48MM piston, new one is 50MM, awesome compression, can barely pull it over.