What's on your bench?

[MustangMike]

can we get a close up of the piston from underneath?

Yea sure, these new cell phone cameras are great, I've taken dozens of pics and still have not run out of film!

2 pics, one each way.

 

[Mastermind]

Who thinks of these things?

View attachment 33757

009?

 

[Stump Shot]

011 Walbro WT, was referring to the fuel line cluster. Why make things that should be simple, so complicated?

 

[VinceGU05]

n

that looks like a 026 carb

aa its a 009 or 010 011 type saw. pain in the butt setup that.

 

[Mastermind]

Germans.....

 

[VinceGU05]

wow.. ok its still got a thick skirt on it. it wont be a small touch that did it.. that would have had to hit the nipple by a couple of mm for that to break out like it did i reckon.

 

[dall]

the nipple would bend before the piston would break off

 

[MustangMike]

the nipple would bend before the piston would break off

I'm not so sure about that. I think hot aluminum is much more brittle than brass, but I could be wrong.

I'm still open to any ideas as to what the heck happened here, I'm just trying to put the puzzle together.

No other missing parts, and all the damaged stuff looks like piston. The muffler is stock, with screen, so nothing big could have escaped.

 

[Tor R]

OK, Close Ups:

it's hard to say on those pictures if the nipple toutch the piston or not. Is it brass or metal plug, brass is harder then aluminium, but it break easily
Line up everything and use long bolts for the jug so you can lift it up and inspect if the piston hit it or not.

 

[mdavlee]

I don't see how the piston can swell more than .002" since cylinder wall clearance is only about .003". Something else went wrong before that was able to rock far enough to hit if it did. Hows the bevel on the bottom of the intake port?

 

[paragonbuilder]

I'm not so sure about that. I think hot aluminum is much more brittle than brass, but I could be wrong.

I'm still open to any ideas as to what the heck happened here, I'm just trying to put the puzzle together.

No other missing parts, and all the damaged stuff looks like piston. The muffler is stock, with screen, so nothing big could have escaped.

Mike maybe it's as simple as a defective piston. Had a hairline crack right from go or something like that.


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[mdavlee]

Mike maybe it's as simple as a defective piston. Had a hairline crack right from go or something like that.


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That's my thinking. Sometimes things like that happen

 

[Mastermind]

Yep.....just replace the piston and move on.

 

[MustangMike]

Well, just to be safe, I'll replace the piston and file down that nipple, it just can't hurt, and there is still the possibility that the wrong nipple is installed. The piston and base gasket were ordered yesterday.

Thanks everyone for the feedback.

 

[MustangMike]

Anyone know what that aluminum saddle does?

 

[Mastermind]

Anyone know what that aluminum saddle does?

It's a deflector of sorts Mike. It directs the intake flow up into the piston to help cool the crown.

 

[MustangMike]

Thanks, I imagine it also serves as a crank stuffer!

It also looked almost like the old rib girdles used to strengthen the engine!

Was much lighter than I thought it would be.

 

[Mastermind]

I think it displaces volume as well Mike. Tech bulletins talk about it cooling crown heat. The exhaust regurgitation system (lol) on those engines overheats the piston.

 

[Magic_Man]

Fall is here time to drag out some projects , bring on the basket cases !

 

[Magic_Man]

Farthest to closest , Husqvarna 350 that's getting an OEM 346 treatment, 028 Super, 028 Standard, Husqvarna 50 basket case that I'm not sure of direction yet, Husqvarna 340 basket case to be figured out, and my 460 Magnum that may end up being a keeper.