Thread Size

[GTR]

Hi Guys

Can anyone tell me what size the thread is for the fuel inlet nipples on a K&B 21 carb? Would like to plug with a grub screw but want to be able to reverse it later on.

thanks in advance

 

[Propjockey]

Looks like 6-32...but couldn't guarantee it.

Ummm.....how you plan on getting the fuel in? :blink:

 

[ScottVanSlooten]

The thread size is 6 - 32 for the fuel nipple and 10 - 32 where the needle gose in . I would think that you are looking at using a third ch needle so you will not need that in your way either. I have made a new end for the carbs and put a OS in flight needle right on the carbs . Works better then mounting it to far away from carb. Scott

 

[GTR]

Hi Guys

sort of right - the end where the needle fits is 10-32 perfect location for a 90deg pressure fitting (new inlet) but I need to plug the old inlet. Thread is finer than 6-32 may be 6-40 if there is such a beast. Strange thing a 3.5mm screw fits perfectly.......hmmmm

Somebody must know for sure. :blink:

 

[SColby]

I'm not sure what size thread but there is such a thing as a 6-40. The 3.5 is probably working do to there really isn't any difference in size. the sizes are...

6-40----.113

3.5mm----.1142

These are the tap size I beleive. But for comparison you can see that they are almost the same. On a tap chart they are right together. Here is a chart for ref.

View attachment 2334

 

[GTR]

Hey thanks for the chart that should be helpful. Should be able to loctite the 3.5mm screw in. I think it will do the job.

 

[SColby]

No Problem. I have the other side as well if you would like it.