A couple of SU questions

[grannyknot]

 

There is a fine screen filter in the banjo fitting, but it is after the main and finer filter, so just wondering if it is needed?

Has anyone found new bushings for the main butterfly valve shaft or a way to stop the air sneaking through the gap?

Is there a trick to getting the needles out without damaging them? I've unscrewed the slot head screw holding them in place but can't get the to budge.

 

Edited July 3, 2023 by grannyknot

[AK260]

Can’t comment on the banjo question but the needles on all 3 sets of my carbs just slide out when undone. I strongly suspect you are battling corrosion.

Just use the usual penetrating oils etc and soak then gently try to move them out. Good luck fella.

[z3beemer]

After you remove the screw from the slide that holds the needle you can grab the needle up high right near the bottom of the slide with a pair of vise grips and twist it while applying downward pressure.  Don't worry if you get some marking on the needle from the vise grip.  That part of the needle never gets into the nozzle (jet).  I would still soak it some sort of penetrating oil before attempting the removal.  Acetone and automatic transmission fluid is cheap and works well.  Use a 50/50 mix.

[z3beemer]

By the way those filter screens are readily available. I think I got mine online for like $1 a piece.

[Captain Obvious]

6 hours ago, grannyknot said:

There is a fine screen filter in the banjo fitting, but it is after the main and finer filter, so just wondering if it is needed?

Has anyone found new bushings for the main butterfly valve shaft or a way to stop the air sneaking through the gap?

Is there a trick to getting the needles out without damaging them? I've unscrewed the slot head screw holding them in place but can't get the to budge.

First Q - Depends on your definition of "needed". I've seen junk in those filters, so I consider them cheap insurance as a "last chance" filter. Would catch anything that comes off the inside of your fuel pump or the rubber hoses between the main filter and the bowl. As mentioned above, they are still available (for the round tops) and they're not that expensive. I'd run 'em.

Second Q - No. And I doubt the real issue is the bushing. I bet the problem is more the shaft than the bushing. Once you wear through the hard chrome into the soft brass underbelly, it wears pretty easily. You comfortable with precision stuff on your lathe yet?

Third Q - My (non-expert) method is to use a thin layer of rubber sheet (1 mm thick rubber gasket sheeting) on the jaws of your bench vice. The rubber provides a little stickier surface to grip the needle along with some cushion and compliance to spread the force. Grip up high, slight twist and pull. Don't chew your needles up with pliers.

[Patcon]

I've got some magnetic rubber vise pads that might work good for the needles.

 

[dutchzcarguy]

6 hours ago, Captain Obvious said:

My (non-expert) method is to use a thin layer of rubber sheet (1 mm thick rubber gasket sheeting) on the jaws of your bench vice. The rubber provides a little stickier surface to grip the needle along with some cushion and compliance to spread the force.

I often use some soft copper plates that protect any part that i put in my vice, i got it from a plumber, also the slater has some left overs that you could use. 🙂

[grannyknot]

Thanks guys, I got the needles out, cemented in with gasoline varnish.

 

[davewormald]

I tried (carefully and briefly) to get the needles out of those a couple of years ago when I was first proving to myself that the engine would run after sitting for 20 years. I wasn't able to get them out, but I wasn't willing to damage them, because I wasn't sure whether either of the two sets in the replacement kit were the correct profile. I did spend some time looking for the filter for the banjo fitting, without any luck. I've tried again this morning, again with no luck. I'm assuming these are from my car, of course! 

[Captain Obvious]

I doubt the needles in the replacement kit were the correct profile.

[grannyknot]

6 hours ago, Captain Obvious said:

I doubt the needles in the replacement kit were the correct profile.

Noooo, don't tell me that, one of the needles got bent removing it.

Far left and middle are original, right is the closest match.

[grannyknot]

8 hours ago, davewormald said:

I tried (carefully and briefly) to get the needles out of those a couple of years ago when I was first proving to myself that the engine would run after sitting for 20 years. I wasn't able to get them out, but I wasn't willing to damage them, because I wasn't sure whether either of the two sets in the replacement kit were the correct profile. I did spend some time looking for the filter for the banjo fitting, without any luck. I've tried again this morning, again with no luck. I'm assuming these are from my car, of course! 

The 2 filters that are original are in good shape and if you want me to I'll re use them, I was just questioning why they were there.