carb parts

Sat Aug 10, 2013 4:03 pm

I just disassembled the carb on a Cub, question is:

Should the needle valve have a wire/spring attaching it to the float? The value has a groove around the bottom end like there should be something attached to it.
I have looked at several kits (the parts scheme) and none show a wire/spring.


thanks for your help.

Brazos

Re: carb parts

Sat Aug 10, 2013 4:12 pm

There is not typically a wire on the cub carb. :D

Re: carb parts

Sat Aug 10, 2013 4:24 pm

Some carbs have a small wire clip to hold needle against float arm.

Re: carb parts

Sat Aug 10, 2013 5:33 pm

Should not be one on a cub. However some people will try to put one in it out of a cheap carburetor kit. I hjave seen them on them but the carb was sent to me to fix :D
Boss

Re: carb parts

Sat Aug 10, 2013 9:01 pm

Image

Re: carb parts

Sun Aug 11, 2013 8:15 pm

If the carb is a 3/4 inch I/H updraft it will not have a spring. If it a Zenith it may or may not.

Re: carb parts

Sun Aug 11, 2013 10:23 pm

Image

Re: carb parts

Mon Aug 12, 2013 8:01 am

The purpose of the wire is to pull the needle down as the float lowers. I have not seen one on a Cub but if it would fit, it would be potentially helpful in preventing a stuck needle The fuel pressure is quite low on gravity systems and the needle depends mostly on gravity to open it. With fuel pump systems, the line pressure helps open the needle.

Re: carb parts

Mon Aug 12, 2013 9:21 am

the clip is used on the cub carb when you have aftermarket rubber tipped needle valve. They tend to stick in the seat especially when new.

Re: carb parts

Tue Aug 13, 2013 8:33 pm

Thanks everyone for the info, evidentally the carb on this cub does not need a spring. it set in the shop for two years without being started so when it would not start it , I thought I remembered there being a spring attaching the valve to the float . Anyway long story short ,after a thorough cleaning and reassembly of the carb, the old cub fired on the first try. Sounds sweet!!
Brazos

Re: carb parts

Wed Aug 14, 2013 7:34 am

Brazos:

That is usually what happens. These carbs are very simple and when properly maintained provide excellent performance. Even after sitting for a long time, a good cleaning is usually all that is needed.

The Cubs do sound sweet when idling don't they. A well tuned C-60 is a musical instrument :D