bad bearing?

[Megunticook]

Was out bucking a maple tree yesterday with my Husqvarna 55 Rancher I've had since I bought it new in 2004. Generally runs great, although I did have to replace the cylinder and piston a few years ago after it lost compression.

So the saw chain seemed like it got pinched at one point, I pulled the saw out of the cut, and then it stalled. When I tried to restart it I pulled once and then the next pull everything seemed to lock up. I let her cool down then brought her to the bench for a closer look. Still didn't want to crank at all, I removed the sparkplug, the muffler (so I could see if the piston was damaged/burned), the bar/chain, and the starter assembly, I was able to turn the crank but it seemed like it wanted to bind at top dead center. No sign of damage or burned areas in the part of the piston I could see.

The main bearings have never been replaced in this saw. It cuts 2-3 cords of firewood every year. You think it's time for a complete rebuild? Or is something else going on here?

Should I just tear it completely down at this point? I don't have a backup and am right in the middle of processing next year's firewood, so would love not to have a lot of down time, but maybe I don't have a choice here.

Thanks for any advice.

 

[singinwoodwackr]

Pull the clutch and inspect

 

[Michael E]

Clutch and starter assembly would be next on my list. Remove and try to turn over the saw again.

 

[Megunticook]

Already pulled the starter assembly. Pulled the carb and took a peek into the cylinder intake, it looks to me like part of the piston is missing from the bottom edge of the piston to part way up the sidewall there's a wedge-shaped area where the metal is missing. So...piston failed and the fragments jammed things up?

I'll pull the cylinder and have a closer look. Why would that happen? I replaced the factory piston/cylinder with an aftermarket about 6 years ago.

Overheating? Cheap parts?

 

[SteveSr]

Already pulled the starter assembly. Pulled the carb and took a peek into the cylinder intake, it looks to me like part of the piston is missing from the bottom edge of the piston to part way up the sidewall there's a wedge-shaped area where the metal is missing. So...piston failed and the fragments jammed things up?

I'll pull the cylinder and have a closer look. Why would that happen? I replaced the factory piston/cylinder with an aftermarket about 6 years ago.

Overheating? Cheap parts?

6 years on an AM piston? You got more than you money's worth. OEM piston would likely still be running. Now you have to worry about collateral damage to the cylinder, crank and bottom end bearings.

 

[Megunticook]

Should I just rebuild the whole thing since I haven't done the lower part in 20 years? Love the saw, would like to run it for another 20 years!

Any tips on quality parts? Or companies to avoid?

 

[muddy42]

After 20 years, personally Id consider replacing a 55 rancher.

Yes you can rebuild it, but new parts will cost more than a replacement. With a new saw you should get reliability and all the technological advances, anti vibe and weight reductions of the last 20 years. Personally I keep >70cc saws going and rebuild them for fun and the occasional large job, even with good aftermarket parts, but the 50cc category is much more of a generic workhorse. Also I find it much more fiddly and harder to rebuild these small saws.

Finally those ranchers have two aspects I don't like. firstly there is the way that the engine is choked simply by pressing on the air filter - this often causes the air filter to pop off. Secondly the impulse line boot is a bit plasticy and can leak.

 

[diver64]

I'd get a new saw and fix the Rancher with after market parts and keep it as a back up.

 

[SteveSr]

Should I just rebuild the whole thing since I haven't done the lower part in 20 years? Love the saw, would like to run it for another 20 years!

Any tips on quality parts? Or companies to avoid?

A complete tear down and inspection is required to assess the damage. Only then can you make a determination of cost to repair. Obviously if you want it to last you need to use OEM parts.

Also if this has a plastic intake block it needs to be checked for warpage at the carb interface. If it has a plastic clamp on the boot at the cylinder it needs to be replaced with a metal one.

 

[Gord404]

After 20 years, personally Id consider replacing a 55 rancher.

Yes you can rebuild it, but new parts will cost more than a replacement. With a new saw you should get reliability and all the technological advances, anti vibe and weight reductions of the last 20 years. Personally I keep >70cc saws going and rebuild them for fun and the occasional large job, even with good aftermarket parts, but the 50cc category is much more of a generic workhorse. Also I find it much more fiddly and harder to rebuild these small saws.

Finally those ranchers have two aspects I don't like. firstly there is the way that the engine is choked simply by pressing on the air filter - this often causes the air filter to pop off. Secondly the impulse line boot is a bit plasticy and can leak.

I think they did away with that choke setup back on the 50 and these have a choke assembly-51&55- pretty easy saw to work on - they are not a clam - the best thing to do is pull the jug and see what damage has been done and why and go from there, seen a number of them go from the imulse plastic plastic leaking because they do not fit tight in the boot anymore

 

[Megunticook]

Thanks for the tips, I will tear her down and see what we find. I guess at this point given the age of the saw I should just plan on rebuilding everything.

Yes, the choke control on the 55 Rancher is just a lever you pull out right by the ignition button.

A new 455 Rancher is about $550, seems like I ought to be able to rebuild the 55 for less than that. No?

Where's your favorite source for parts?

I'll tear into it tonight and post some picks. Still curious what caused the piston to break. I'm trying to find my record on the top end rebuild I did, but now that I think about it I believe I used an OEM Husqvarna cylinder and piston, but can't seem to find the receipt anywhere. Normally I take notes on all this stuff but apparently didn't in this case.

 

[irhunter]

Thanks for the tips, I will tear her down and see what we find. I guess at this point given the age of the saw I should just plan on rebuilding everything.

A new 455 Rancher is about $550, seems like I ought to be able to rebuild the 55 for less than that. No?

I suggest not planning on anything until you have the cylinder off. If the bearings feel good, I'd continue to run them.

Regardless of how good/not-good the 455 is...please know, it is a plastic-bottom clamshell farmer/rancher saw.

Your 55 is a mag-case semi-pro saw.


Roy

 

[Mad Professor]

Should I just rebuild the whole thing since I haven't done the lower part in 20 years? Love the saw, would like to run it for another 20 years!

Any tips on quality parts? Or companies to avoid?

OEM.

 

[irhunter]

BTW, before pulling the cylinder is a good time to pressure and vacuum test the case.

I have had excellent results with Caber rings and Meteor pistons. I have also used Hyway pistons without issue. While I have only done a dozen-or-so melted pistons, I have never had to replace a cylinder.

You probably won't, either.

Roy

 

[SteveSr]

I'll tear into it tonight and post some picks. Still curious what caused the piston to break.

Usually the intake side of the piston skirt wears due to dirt ingestion. Eventually the skirt gets thin enough and breaks. How good is your air filter type and maintenance?

I'm trying to find my record on the top end rebuild I did, but now that I think about it I believe I used an OEM Husqvarna cylinder and piston, but can't seem to find the receipt anywhere. Normally I take notes on all this stuff but apparently didn't in this case.

The OEM parts mat have casting information on the cylinder near the bottom. The piston may or may not have markings on the crown. Post some photos and someone can probably tell if these are AM or OEM parts.

Also, be careful if these are plastic caged bearings that might have had the cages damaged by pieces of metal floating around in the crankcase.