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1974 TY250 piston arrow / window direction

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I have ran across a discrepancy in what I have and what I have read and seen.

I have a stock and aftermarket stock size pistons. Both have the windows on one side and the arrow on the other.

The parts diagrams I have looked at all show the arrow and windows on  same side facing forward toward exhaust.

Am I missing something or is something not right here.

I am about to put the piston in with windows toward exhaust but the arrow will face back which goes against every piston I've ever installed.

 

Screenshot_20220820-114452.png

16610212180942882624497163964535.jpg

Diagrams copied how many times in 50 years. LOL It helps to understand mechanics of 2 strokes in the first place. We went decades with barely any real information, except the one between our own ears.

  • Author

Thanks guys.

Follow the arrow and not the holes.

I usually only have holes in my pistons after I ride it.

I once purchased a non-running 2 stroke bike at a cheap price.

The only fault was the piston had been fitted the wrong way round.

(  That was the only lucky purchase I have had,  most non-runnners I have got involved in have been  much worse than expected )

On 8/20/2022 at 11:29 PM, lineaway said:

The holes go to the intake side.

Assuming it is a reed valve model. They MUST be

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