Zenoah 29cc kit

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t2boats

t2boats

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Hi all,

Fitted the 29cc block kit to an existing 23cc bottem end, however the piston crown is marked with a little arrowon the edge of the crown, does this point to gas flow, ie): towards to the exhaust, or should it be pointing to the air inlet from the carb??

Thanks in advance! :)
 
A quick reason for the arrow and the proper piston direction.
The ring comes together on the ring pin of the piston. The area it comes together on is hidden or covered when going up and down in the head by the center drop in the intake port. This is why the intake is not large like the exhaust port. Without the ring pin and ring ends covered by the intake drop they would catch the port and tear up the head.
If you install the piston backward the ring ends that come together at the ring pin would eventually snag the top of the exhaust port and tear up the head.;)
 
LOL....

Here are some photos to go with the last post:

Here is the ring just showing in the exhaust port.
DSC05025.webp

Here is the drop in the intake port that covers the ring ends.
DSC05023.webp
 
yes it show flow thru cylinder, and all above is correct. lol


how much fuel thru the 23? when boring up, even in stock mode, its a good decision to double check the crank bearings well, and replace if you even think they are funny. i generaly replace my bearings ever 2nd re-ring as a rule of thumb, unless otherwise needed.
 
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