blew it's stack

[Blaaster]

Wiggle in the conrod has nothing to do with why the rings broke.

You stated that it was running a #230 main jet with a FMF pipe, correct me if I am wrong, thats what could have caused the carnage.

Or could it have been a combination of the above, and a piston not fitted with ring locating pins.

My mods before were 230 main jet FMF pipes on a stock carb, motor bored .40 over.

No need to correct me, it was a #230.

 

[Racer51]

Wiggle in the conrod has nothing to do with why the rings broke.

You stated that it was running a #230 main jet with a FMF pipe, correct me if I am wrong, thats what caused the carnage.

Yes sir it was, I made a mistake in the last post. I ment side to side wiggle isi'nt a dealbreaker is it. Also to my exponential delight I literaly just now went to look at the rod and realized it has a stock stroke Hotrods crankshaft in it as well. I:I
In short I believe running lean caused the locating pins to wear away and let the rings rotate and break it off in my butt. (sorry for the language) I think that sums it up. Thanks a ton I owe you big Blaaster and sicivicdude

 

[Blaaster]

When you finally have your new motor assembled and ready to rock, get back to us and we can talk you through the jetting and break in process, so this will not happen again.

 

[sicivicdude]

Thank you sir. I'm planning getting ahold of slick later tonight and seeing if he's got any on hand (he probably does)
2) yes the lid was on but I figured I'd squease a little bit more out of it with the lid off. Not that it was run with the lid off while the 260 was in there at the time. So I amgonna find a 290 and put her in come monday.
# Ok the ring land thanks for teaching me that term along with locating pin But to clarify the ring gaps have to be at opposite ends of the center line/piston pin? Also both locating pins are gone there are not in the piston...........................Would a very very very slight wiggle in the crankshaft rod cause this kind of damage over time???

Slick's a good guy and he'll have you hooked right up with that leak down tester. They're basically essential tools for any 2 stroke owner (not just blaster and not just rebuilt blasters)

Any time you change the amount of incoming air, you need to match that with more incoming fuel. Approximately 30% of the cooling capacity of a blaster engine is provided by the incoming liquid fuel vaporizing and cooling off the piston/cylinder. Lean conditions not only generate more heat (lean fires burn hotter) but there's less fuel coming in to cool off the components! A very dangerous situation....
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The ends of the piston rings should be about an inch away from each other on the intake side of the piston basically one above each of the intake window. The rings are grooved on the ends to fit around or on top of the locator pins and the rings should drop into the grooves and the cylinder should drop over top of the piston with little effort and some guidance. If it doesn't you should stop IMMEDIATELY and figure out why. The locator pins are pressed into place during manufacturing. Enough force on the side of one could potentially knock it loose from the hole.

Also another thing to think about, the pins are steel and the piston is aluminum. If you were running it lean and the piston crown was especially hot, perhaps the pins just lost their press fit and fell out

The crankshaft is supposed to have a certain amount of "wiggle" to it. The book states .016-.028" side to side with basically no up and down.