Let's play diagnose the farm boss chainsaw.

[towingace]

Congrat's! What are the chances of that happening twice? I have done the 'ol "I'll remember that next time" scenario myself, only to have to remind myself all over the hard way. It sounds like you got a new cylinder, if so, would the old one be for sale?

 

[old-cat]

Problem solved. I have finally discovered the issue. I'm fairly thoroughly angry at myself for my poor memory. The piston had a piece of skirt missing from the intake side (pics later). I'm mad at myself for two reasons:
1. I have encountered this previously and went through a long diagnosis process for that. It was an 029 Super.
2. If I had been more diligent in my cylinder inspection, I could have seen this issue as it would have been visible through the intake port. And I had multiple opportunities to view it during all the carb changes. Duh!
Rather than just change the piston, I put in a new Huztl kit (after spending some time on it with the grinder)
I haven't put it in wood yet but do have the saw ready to go with bar and chain. I can't believe how many hours I've invested into this critter. Maybe gonna put it in my line up for a while and extract my vengeance from it.
Anyway, this long saga is coming to a close. Thanks again for the ideas and support.

Just a little reminder that you're human, eh?

 

[lone wolf]

Just a little reminder that you're human, eh?

At least he admitted it .

 

[old-cat]

At least he admitted it .

He don't have to be mad at himself. That's what I'm saying.

 

[towingace]

Hey Old-Cat, I guess you were awarded the winner of the "guess what it was" contest a little prematurely. Better early than never.

 

[Wood Doctor]

Rather interesting how may ways that that these 029/290/310/390 saws can fail. I just wish that they made them easier to fix. That skirt piece could have banged around quite some tine before being blown out of the exhaust. Or, it could still be in there somewhere. Now, of course, you have to think back and try to determine what caused it to break loose and wreck the engine.

The beat goes on.

 

[lone wolf]

Rather interesting how may ways that that these 029/290/310/390 saws can fail. I just wish that they made them easier to fix. That skirt piece could have banged around quite some tine before being blown out of the exhaust. Or, it could still be in there somewhere. Now, of course, you have to think back and try to determine what caused it to break loose and wreck the engine.

The beat goes on.

Loose piston to wall and slapped itself is my first thought. A lot of dirt will wear them out and cause this.

 

[fearofpavement]

Here's the pics. Nice clean exhaust side (what I locked in on)
And really horrible intake side. I did look in the intake to check that side and the piston must've been down and I saw the nice ring area and... Seeing these pics make me feel even more like a dumbkin.

 

[fearofpavement]

So the lesson learned is... Keep looking, eventually you'll find the problem...

 

[old-cat]

Ported piston!!! That should have been a REAL hot rod!

 

[fearofpavement]

Congrat's! What are the chances of that happening twice? I have done the 'ol "I'll remember that next time" scenario myself, only to have to remind myself all over the hard way. It sounds like you got a new cylinder, if so, would the old one be for sale?

I'll be using that cylinder eventually if it passes inspection and could have today but I wanted to get to the end of this episode. I have a piston in stock that will fit it.
I have some other 1127 cylinders such as MS310 that I probably won't use as there isn't much aftermarket support for it. (and I won't fix one of these saws with oem parts unless I have used and serviceable ones)

I usually always upgrade them size wise but I think there is a price point for the MS290 and may build up a few of those in the future. (the kits are cheaper)

 

[lone wolf]

Well hell now what are we supposed to figure out? opcorn:

 

[KUBOTA OWNER]

What happened to the piece of piston skirt? You would have though it would have made a lot
of noise in the lower end.

 

[fearofpavement]

There was a lot of aluminum dust and grit in the lower end. Saws are pretty noisy so not sure if the user noticed it. I expect this piece broke off and got ground up fairly quickly and the saw probably didn't see more use after that... I probably ran it more trying to troubleshoot it than the previous user did after the failure.

 

[KUBOTA OWNER]

I give you a lot of credit for staying with it, I was a service manager at a garage and when we could
not fix a car or truck after working on it for a week or so I would start to dream about it at night.--
One time the next day I came in and asked the tech, if he checked this, and he said no but will. And low and behold
he comes back to my desk and said that's it!! --and wants to know why I though about doing that. -- When I told
him I had a dream last night.---That why they pay me the big bucks!!! ---Then when ever we had a problem after
that I would say. "hey maybe I should take a nap" Ha, Ha.. ---Retired now, only fix saws.

 

[towingace]

A lot of saws end up in the "donor pile" at saw shops because of small problems. Sometimes, diagnostic time alone is enough to deem the saw "not worth fixing". That's where people like us come in. Drag that sucker out of the pile, take it home, sink countless hours into it, spend a little money on it (sometimes a little too much), make it whole again, and finally the rewarding brrraaaapp! Now you can take in the proud feeling of accomplishment, knowing you saved that saw from it's untimely fate and making it a living , breathing , cutting machine that it was made to be. i

 

[1Alpha1]

That wasn't even on my short list of possibilities.................

 

[redfin]

I try to grasp the physics behind such issues. In effect this was a very long intake duration. Was this just causing very low tranfer velocity?

 

[fearofpavement]

What threw me off on this one and the one some years back was the decent compression and good idle. Both could have been visually diagnosed through the intake port. Sure hope I can remember this episode if I encounter another one in the future...

 

[VinceGU05]

What threw me off on this one and the one some years back was the decent compression and good idle. Both could have been visually diagnosed through the intake port. Sure hope I can remember this episode if I encounter another one in the future...

look left and right when crossing the road... look in output and input holes on the cylinder every time too