float needle pin

[rich_mcd]

I took my carbs apart yesterday looking into why it is leaking gas at the bowls. Thought it could be the gaskets. I decided to take the floats off and look at the float needle. I did the wiggle test.....o-ring needs replacing.
But upon inspection of the pin inside the float needle they are different heights. The taller one of the two is just over 1 mm and the shorter one is just shy of 1mm. I know the difference is negligible but is that enough to replace them at the same time I do the o-rings. I honestly dont know what the spring in the float needle even does. I dont want to put it all together to just tear it down again.

Thanks in advance.
Rich

 

[XSLeo]

As long as the pin moves freely it's fine. As the float bowl fills the float lifts the needle. Once the needle seats the flow will stop. The spring loaded pin acts like shock a absorber to prevent sloshing of the fuel from pulling the needle from the seat.
The book says to adjust the float hieght by holding the float so the tang on the float just touches the pin without compressing the pin. This can be tough. If you rock the carb body over so the float hangs free and then rock it so it just touches the pin makes it easier to measure.
Once the adjustment is made it compensates for the minor difference in pin heights.
Leo

 

[rich_mcd]

awesome leo, Thanks a ton. I just called my yamaha dealer and they wanted $29.06 per needle and $3.35 per o-ring. Do you think a 1.5mmx7mm or a 2mmx7mm o-ring work as opposed to the 1.5mmx7.5mm that is listed?. (thats all I can find local)

 

[XSLeo]

I don't think one larger will fit without damage. Others have found those o-ring at Mc Master Carr. They come in packes of 50 or something like that. If some opne who has gotten them thoer reads this they might tell you more about it. Maybe even sell a few extras for a good price.
Leo

 

[5twins]

The 1.5 x 7 's should work. The 2mm ones would be too fat.