What Could Have Caused This

[oldbigred]

Title pretty much says it all. When I opened up my Homelite SXL I found what is in the attched pic. Just on the exhaust port side. The rest of the cylinder and piston looked fine. Also would my cylinder be reusable...the scoring seems to be mainly below the port, but removed almost all the plating in two or three "scratches". Could it be replated? On a side note, how far should you torque the rod caps on these saws.

 

[country boy]

Title pretty much says it all. When I opened up my Homelite SXL I found what is in the attched pic. Just on the exhaust port side. The rest of the cylinder and piston looked fine. Also would my cylinder be reusable...the scoring seems to be mainly below the port, but removed almost all the plating in two or three "scratches". Could it be replated? On a side note, how far should you torque the rod caps on these saws.

i cant be of any help but that looks really bad !!!!!

 

[ericjeeper]

Looks a lot like a cold seizure to me.

But I am sure someone will shoot my theory down.. shortly. LOL

 

[pioneerguy600]

Title pretty much says it all. When I opened up my Homelite SXL I found what is in the attched pic. Just on the exhaust port side. The rest of the cylinder and piston looked fine. Also would my cylinder be reusable...the scoring seems to be mainly below the port, but removed almost all the plating in two or three "scratches". Could it be replated? On a side note, how far should you torque the rod caps on these saws.

IMO. This piston is ruined and likely the cylinder also. It would be cheaper and easier to pick up a good used set off ebay or from one of the ebay stores as Homelite parts are usually listed every week on ebay. To replate and resize a cylinder would be costly but can be done and has been discussed on this forum before with company`s and addresses that could be contacted for a price, I was quoted 250 plus shipping to have it done up here in the Maritimes. I have picked up good running complete saws for75-100 off ebay. The homelite repair manuals I have say to torque the allen head rod screws at 55-60 inch lbs for the No. 8-32 size screws and 70-80 inch lbs. for the No.10-32 size screws ,these are for the XL series saws but the SXL is not specifically mentioned there but if the screws are the same size it should work ok.

 

[oldbigred]

Thanks for satisfying my curiosity...I think :greenchainsaw: pioneerguy600 - you wouldn't know what your manual says about torquing the cylinder by chance? as i already have a p/c kit and the rebuild is kinda underway. thanks.

 

[Sprig]

Ow!

No pro but that looks pretty much hooped, maybe a chunk from inside the muffler got lodged in there? Had to be a piece of metal from somewhere...............would a sloppy piston beat itself up on the edges of the port maybe? dunno but curious, never seen damage like that before but I'm sure the mech's have.............

opcorn:



Serge

 

[wood4heat]

Looks like you got something in there, how do the bearings feel? Usually when I've seen damage like that it was from a wrist pin bearing or lower rod bearing coming apart.

 

[oldbigred]

I think it might have been lower bearing?? As it has a lot of play if you try to turn the piston the piston/rod assembly 'wobbles' on the crank. If you can picture that.

 

[Log Splitter]

Some would say it's a result of suckback.

Keep the posts coming, Oldbigred. We like reading saw rebuilding threads, it's a lot better than arguing about mix.

 

[sawinredneck]

Some would say it's a result of suckback.

Keep the posts coming, Oldbigred. We like reading saw rebuilding threads, it's a lot better than arguing about mix.

It was all I could do not to post that!!! Then you do it anyway!!!!!!

Something came apart!!! That is metal inside!

 

[oldbigred]

haha yeah...would you mind explaining 'suckback' as I can't say im 100 percent familiar with the term.

 

[pioneerguy600]

Thanks for satisfying my curiosity...I think :greenchainsaw: pioneerguy600 - you wouldn't know what your manual says about torquing the cylinder by chance? as i already have a p/c kit and the rebuild is kinda underway. thanks.

Yes the cylinder bolts are said to be either 1/4 or 5/16 and given as 70-80 inch lbs. Ring end gap 0.070 new and not over 0.085 worn out. Pioneerguy600

 

[Ole Farmerbuck]

haha yeah...would you mind explaining 'suckback' as I can't say im 100 percent familiar with the term.

its when your gf......ah never mind!

 

[oldbigred]

I wondered when someone would comment on that. ha!

 

[Log Splitter]

haha yeah...would you mind explaining 'suckback' as I can't say im 100 percent familiar with the term.

I'd say do a search on 'suckback', but I'll save you some time and point to the thread that contains the most information.

http://arboristsite.com/showthread.php?t=49424&highlight=suckback

 

[sawinredneck]

Or lack of information as the case may be!

 

[oldbigred]

Here's the cylinder from that same saw. Good/No good? Dosen't appear to be near as bad as the piston.

 

[bore_pig]

Run a dingleball hone in that cylinder. Looks like it's just smeared. Might be reusable. I think what they mean by suckback is cold air coming back through the muffler and getting into the cylinder. Do you have a muffler mod on that saw?

 

[oldbigred]

Yeah I'm not sure, there are a couple deep scratches but I don't think it removes anything but the plating in these places (as if thats not bad enough) The lighter areas are were it appears to still have plating, just worn. The darker streaks are the deeper scratches. I have a new cyl just wondered if this one is salvageable. No muffler mod, just a stock SXL quiet tone muffler. I'm not sure but i think it may have been cold seizure or a lower end failure (how much play should it have?)

 

[wood4heat]

Here's the cylinder from that same saw. Good/No good? Dosen't appear to be near as bad as the piston.

Looks like a goner to me. There are places you can send it to have the plating redone, probably cost as much as the new cyl though.