Cooked Crank

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Here is a better picture . The only opening to the crankcase is the impulse hole. And here is a picture of the piston at the top of the stroke, skirt is covering the intake completely.image.jpgimage.jpg
 
Actually it was brought to me by a customer and handed me at carb kit and said all this just needs a carb kit. Of course I checked the compression first. So I can't say that I have seen it run ,. And don't you just love it when they diagnose it for you
 
I'm confused at your confusion.

Bro, seriously though go back through this thread very carefully and read what you have been told, then apply it to the saw, then please oh please only respond with an apology for those who were trying to help you.

A lot of smart guys in this thread. I promise none of them are magically wrong but all have the same exact story about how it works.
 
I use fuel that is in a can and pre-mixed, this is a customer's saw and there was oil in the gas. I want to know how oil makes it to the crank. Unless I am missing something...there is no possible way for oil to get behind the rings.

Someone lets you work on their saws? And you nothing about two strokes? And you use expensive gas pre-mixed from a can?
:ices_rofl:

Question: Besides working on a customers saws, someone trusts you using their tools too?

On second thought, I've got this green Wild Thingy I found in the metal pile at the landfill, I think it needs a carb kit...........
 
I use fuel that is in a can and pre-mixed, this is a customer's saw and there was oil in the gas. I want to know how oil makes it to the crank. Unless I am missing something...there is no possible way for oil to get behind the rings.

Do a search on piston ported two-stroke engines.

BTW, there are also reed-valve and rotary valve. But they all get the oil mixed with the fuel to the crank, before it goes to the combustion chamber.

P.S. Here is a tip before you pick up a wrench next time, clean it up first.
 
It may very well have the wrong piston. The intake should be open with piston sitting against the head.

Picture posted above piston is not close to TDC. Bore is 49mm stroke is 34mm. So the bottom of the skirt should be up a little higher than 70% bore diameter from bottom of bore. Maybe piston is hung up on a chunk of bearing material?

Some closed port pistons have windows around the pin to help feed the lower transfers, some like the TS400 just have big cutouts on the sides of the piston below the rings.

I hope this thread provides some more entertainment when I get up in the morning.......
 
Picture posted above piston is not close to TDC. Bore is 49mm stroke is 34mm. So the bottom of the skirt should be up a little higher than 70% bore diameter from bottom of bore. Maybe piston is hung up on a chunk of bearing material?

Some closed port pistons have windows around the pin to help feed the lower transfers, some like the TS400 just have big cutouts on the sides of the piston below the rings.

I hope this thread provides some more entertainment when I get up in the morning.......

I was thinking it was hung up as well. I prefer non windowed pistons personally, side feed transfers or not, as long as the bridge has clearance.

Definitely an odd thread, but good for a laugh or two at least.
 
Thanks Franny, how can the transfer port charge get to the crankcase with no opening? The gasket is correct, it's the cylinder that is not. Again, there is no way in this case for the crank to get oil. It can't magically go around the rings, right?
If as you say there is no way the fuel charge can enter the crankcase my question is How did the motor run to "cook" the big end? no mix in the cranckcase =no go, i would guess a straight gassing at some point & may be the cyl was changed without the bottom end being fixed. Could I add that the way you come across in some of your posts you are less likely to receive help if that is what you are requiring or do you know & are trying to catch other posters out
 
so far I'm just getting a lot of egotistical pompous douche-bag responses, no wonder the small engine repair industry has such a big black eye.
I'm not sure helping you with such a bad know-it-all 2stoke trophy winning attitude is a good idea at all. It will encourage you to work on other 'paying customers' saws which I don't think we should support at all. If you wonder why small engine techs are tarnished with a black eye, perhaps a mirror is what you really need. Your frustrated because you don't know what your doing. People round here are nicer with more patience than me to keep offering you help with such attitude.
 

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