Strange find inside a ms390!!!!!

[Khntr85]

Hey guys I have been really busy lately and haven’t been able to rebuild any saws....I have had a ms390 that is next in line and it’s been on the bench awhile now....

I have found many funny and strange things in saws as many of you guys have...this one ranks at the top of the list for me....

The pictures will speak for themselves....I just wish there was a way to find out how long this saw ran like this....the piece of metal was definitely “stuck” to the top of the piston for awhile.....I got this saw in a truck load of other dead saws, so I have no back round in the saw itself....

Anyway what do you guys think....

 

[Mkinslow]

Did that come off the saw itself or is it foreign

 

[Khntr85]

Did that come off the saw itself or is it foreign

It was actually in the engine.....

What I can’t understand is was it on top of the piston for a long time, or was it somewere else and just “popped” loose???

 

[Fruecrue]

Interesting. Was the spark plug gap closed?
I can’t see it ever running that way.
For what it’s worth, HL Supply has just received shipment of the pop-up pistons designed for this saw.

 

[breese]

Ok... So what is the Squash according to that plate??
LOL

 

[Khntr85]

Interesting. Was the spark plug gap closed?
I can’t see it ever running that way.
For what it’s worth, HL Supply has just received shipment of the pop-up pistons designed for this saw.

I will look when I get home....all I know is that slug was actually inside the engine when I cracked it open...I can’t remember where I found it, but when I seen the outline of it in the top of the piston it was shocking....I don’t know if the slug as attached somewere and caramel loose or what....It could have been in stuck in the exhaust port and just eventually worked its way loose??

I actually torn this saw down, and took these pics a month or so ago......I got busy since then so it has just been waiting to come back to life...

 

[Fruecrue]

Could that be the stamped rectangular portion of the muffler that serves to cap the baffle?

 

[Fruecrue]

 

[Khntr85]

I thinks it’s thicker metal, but I will look when I get home.....I haven’t looked at it since I tore it down awhile back....I just seen it on the bench last night and thought to myself, I need to get it done, lol

 

[71dart]

Maybe it's a poor man's pop-up.lol

 

[BrokenSVT]

I'm following this one. I had a 390 back in the summer which I picked up for next to nothing. I messed with it within my interest level, and because I couldn't solve its issues and had purchased it so cheap, I eBay'd it as a parts saw with known issues.

Long story short, its symptoms included a metallic clatter when running, and would only run at all on choke. Like I said, it just wasn't interesting enough to me since I had pro saws in every size range I could want by then. I have a video with it running somewhere here...

 

[Mkinslow]

It was actually in the engine.....

What I can’t understand is was it on top of the piston for a long time, or was it somewere else and just “popped” loose???

That’s definitely interesting for sure. I’ve never been inside one of those saws but it doesn’t look like it’s part of it

 

[Jon1212]

Subscribed

 

[BrokenSVT]

Here was my jingly 390...

 

[Jon1212]

Could that be the stamped rectangular portion of the muffler that serves to cap the baffle?

Good thought.

I had a similar thought about the exhaust cutout on the back of the muffler.

 

[Dub11]

Here was my jingly 390...

Sounds like a brigs mower lol. and thats more like a 391 or something with that fancy spring av action.

 

[BrokenSVT]

Sounds like a brigs mower lol. and that like a 391 or something with that fancy spring av action.

Haha yep, I think you're right. Must've been a 391. I didn't keep it long enough to read the name plate.

 

[jacob j.]

Did you scribe that mark around the piece of metal on top of the piston? It looks like to me someone tried to epoxy that piece on there, to raise compression. Perhaps that mark is where they lined it up.

 

[sawmikaze]

Here was my jingly 390...

 

[Czed]

Hey guys I have been really busy lately and haven’t been able to rebuild any saws....I have had a ms390 that is next in line and it’s been on the bench awhile now....

I have found many funny and strange things in saws as many of you guys have...this one ranks at the top of the list for me....

The pictures will speak for themselves....I just wish there was a way to find out how long this saw ran like this....the piece of metal was definitely “stuck” to the top of the piston for awhile.....I got this saw in a truck load of other dead saws, so I have no back round in the saw itself....

Anyway what do you guys think....

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Redneck popup?