Hole in my Cylinder??

seafood10

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6:27 PM
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Jun 16, 2009
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Hey, put together my first 66cc kit and was breaking it in, about 2-3 hours on it and I noticed oil/gas leaking where the head and jug meet, but not apparently leaking from the head gasket as I can tell from both looking at it and ensuring the the head is torqued down, but i can look again to double check. It is almost as if there is a small hole in the jug, when it runs it occasionally makes a loud crack sound as if the muffler was not attached making me think that I am listening to the internal cumbustion via this hole? The bike runs ok at full speed but come to think of it, it has lost a little performance. I am still breaking it in with 16:1 so I am guessing that the is the reason for poor idling.
I have been rebuilding Vespa and lambretta engines for over 20 years so I know my way around 2 strokes but have never seen this before, maybe it's a Chinese thing, I dunno. Any ideas?
thanks
Sean
EDIT: apologize, don't know why the pics got all screwy like that.
 

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Hi,
have you pulled the head & checked the head gasket?

with the head off.... you can also check for flaws in the castings.

good luck & keep us posted.
 
Hi,
have you pulled the head & checked the head gasket?

with the head off.... you can also check for flaws in the castings.

good luck & keep us posted.

Nope, have not gone that far. I was worried that I would need a new head gasket if I remove the head and do not know where to begin to look for a head gasket, but i can always make one I guess.
 
normally, you can get by with reusing your head gasket.
But my guess is it's already blown.

several of our site sponsors have gaskets & parts.
 
normally, you can get by with reusing your head gasket.
But my guess is it's already blown.

several of our site sponsors have gaskets & parts.
Yeah but that's the thing, the gasket looked clean and intact from the outside, not just my opinion that of others as well. Just wondering if the cheap casting left a hole. The bike does run and I can scoot along but there is some leaking going on. Maybe I pull head today, we'll see.
thanks
 
My engine "jug" had a hole in it from the start.
I have a pic somewhere here, the motor runs fine tho.
I patched it with Muffler putty, just in case...
 
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