My 288xp/660 piston swap build...

[AUSSIE1]

I really have no clue...never used one. I thought maybe they had different markings. Are they all marked like the Isky one in TRI955's pic?

Basically the same. Different colour and brand marking would only be the difference really.

The larger wheels help keep it more accurate of course.

Pretty easy to source.

 

[TRI955]

Saw is running really well, full comp chain in a good size oak. I figured out the hard way what makes the center of the log black like that...

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Need to try to salvage this chain now!

 

[little possum]

Saw is running really well, full comp chain in a good size oak. I figured out the hard way what makes the center of the log black like that...

Need to try to salvage this chain now!

Mike, would have been a lot easier to ask me, I could have told you And showed some photographic evidence to prove it. haha

 

[parrisw]

Saw sounds really tight!! You did good.

 

[Arrowhead]

Looks great. Frozen Oak is some hard stuff.

I still say pipe it.

 

[belgian]

I finally got to try my 288xp today with the pop-up piston and was really excited to put her to the test. I was making some pics untill my batteries died before I had the tree on the ground...

The 288 was a real pleasure to run untill I was bucking up the stem, and finally ....bannnng. I knew what was waiting for me...

the tree

the aftermath

The piston did not melt, but my impression is the top ring land gave away. I checked the exhaust port but could not see any hung up marks. The jug has quite a nasty groove in the compression area...so it's toast.

what's your take on it, folks...?

 

[TRI955]

Yes, looks like your correct, the top ring land gave away.

PM me your address again, I have a good jug and piston I will send you.

 

[Arrowhead]

Was it a welded pop up, or turned on a lathe and mill cylinder? I agree, looks like the ring land gave out.

That sucks, but it's cool Mike has the parts for you.

 

[TRI955]

Was it a welded pop up, or turned on a lathe and mill cylinder? I agree, looks like the ring land gave out.

That sucks, but it's cool Mike has the parts for you.

It was turned on a lathe...mine. I'm making sure this is made right...I feel very bad about this. Do me a favor Roland, what was the thickness of the top of the piston on that one? The area that broke off... was it .100" or less? Mine is around .096" and I have had no problems....so far.

 

[belgian]

It was turned on a lathe...mine. I'm making sure this is made right...I feel very bad about this. Do me a favor Roland, what was the thickness of the top of the piston on that one? The area that broke off... was it .100" or less? Mine is around .096" and I have had no problems....so far.

Mike,

don't feel bad about it....sent you a pm. The intent of my post was to determine the cause of the failure, so we all can learn from it and make it better. Surely not to blame someone's work or anything of that kind.... Mike does not owe me anything.

I'll make sure to measure the thickness and report later.

 

[belgian]

Mike,

I measured the top ring land thickness and ....it's 2,45 mm or .096".

 

[logging22]

Sorry bout your saw brother. That sux.

 

[Winn R]

The piston did not melt, but my impression is the top ring land gave away. I checked the exhaust port but could not see any hung up marks. The jug has quite a nasty groove in the compression area...so it's toast.

what's your take on it, folks...?

I can't find the source, think it was an Italian scooter site, Lambretta?,

Had pics of two stroke piston failures, listed this one on the exhaust side. Said too lean did it.

But I don't know and it's never happened to me.:confusedn: Sorry about your problem.

 

[parrisw]

I finally got to try my 288xp today with the pop-up piston and was really excited to put her to the test. I was making some pics untill my batteries died before I had the tree on the ground...

The 288 was a real pleasure to run untill I was bucking up the stem, and finally ....bannnng. I knew what was waiting for me...

the tree

the aftermath

The piston did not melt, but my impression is the top ring land gave away. I checked the exhaust port but could not see any hung up marks. The jug has quite a nasty groove in the compression area...so it's toast.

what's your take on it, folks...?

Where is the ring ends located? Did maybe ring end pin come loose?

 

[belgian]

Where is the ring ends located? Did maybe ring end pin come loose?

The ring pins are still in their original position.
When installing the piston, I found the rings to be pretty loose in their groove compared to other pistons...that may have caused additional stress to the ring land, but that's just a guess on my part.

 

[TRI955]

Sorry boys, just lookin for my notes....