Boxerworks.com

I took apart a set of 64/32/9 and 10 carbs and cleaned them up for a complete rebuild.

I HIGHLY recommend an ultrasonic cleaner for cleaning up carbs. WOW.

Anyhow, upon inspection, i noticed that the orifice for the Float needle is chewed up.
One carb has a nice brass-like lining to that hole, and the other looks like it was gunked up with a goop or epoxy of some sort.

I know that needle has a small amount of wiggle room in a carb that has the brass fitting so I'm wondering if i should be concerned. Any thoughts?
The 'goop' is very solid so removing it might be tricky and then i'd be left with a hole without the brass lining.
Or is the carb trashed?

Please see the photos so you can see what i am referring to. It is the hole closest to the bottom of the photo.:

You can scrape the crud out by hand. The only thing that matters there is the needle seat. Test it to see if you can get it to seal well and all is good to go. I don't know if it is true, but I hear that Bing USA can replace the seat.

The only way successfully get that seat out without damaging the carb body is to tap the seat and use a slide hammer to pull the seat out. However, I have a feeling that someone has tried to repair a botched attempt at removing the seat.
It now depends on whether there is enough 'meat' left of the damaged seat to be able to run an 8mm tap down there.
The tap to use is a 'bottoming' tap, which has very little taper to it. This sort of tap will allow you to run a thread as far down as possible.
Find a compatible thread bolt and make a slide hammer out of whatever you can find.
Heat the carb body around the seat and use the slide hammer extract the seat.




A little wobble of the needle in the 'good' seat is OK.

If you can get that stuffed seat out, there are replacements available from Bing.

If you get that far, I can help with getting the new seat in.

If the carb body has been damaged by previous attemps at removing the seat, you may be up shit creek.

ME 109 wrote:The only way successfully get that seat out without damaging the carb body is to tap the seat and use a slide hammer to pull the seat out. ...blah, blah, blah, picture, blah, blah...
If the carb body has been damaged by previous attemps at removing the seat, you may be up shit creek.

I just knew you had done this out by shit creek in the only shade for miles around under some scrawny little tree. How'd you stake that new seat in there?

Native /5 wrote:

ME 109 wrote:The only way successfully get that seat out without damaging the carb body is to tap the seat and use a slide hammer to pull the seat out. ...blah, blah, blah, picture, blah, blah...
If the carb body has been damaged by previous attemps at removing the seat, you may be up shit creek.

I just knew you had done this out by shit creek in the only shade for miles around under some scrawny little tree. How'd you stake that new seat in there?

Blah?
Blah he says.
That's what my dog hears when I talk to him.

That's highly intelligent blah from me.

The new seat is a press fit. An interference fit to be precise.
Freeze the new seat, heat the carb body, and quickly whack that sob in there before things get too tight again.

ME 109 wrote: Freeze the new seat, heat the carb body, and quickly whack that sob in there before things get too tight again.

Out under that scrawny little tree? Where'd you find a rock the right size for that seat? You're good.

In the first photo, you can see that the seat seems unharmed. It is just the wall of the hole that is a mess.
How can I test if the needle and the seat are still mating properly?

The seats of both carbs look questionable in the photos from where I sit.
How can you tell the condition of the 'wall of the hole' if the seat is still in place?
If the 'wall' is damaged, your in trouble.
If the carbs were rare, they could be repaired with oversize seats.

jjwithers wrote: How can I test if the needle and the seat are still mating properly?

The easiest way would be to set up the carb with fuel coming in the top and the needle gently held against the seat. Imagine how little pressure the floats impose and duplicate that. Should give a pretty good idea.

Airbear wrote:
The easiest way would be to set up the carb with fuel coming in the top and the needle gently held against the seat. Imagine how little pressure the floats impose and duplicate that. Should give a pretty good idea.

What about a real world test Charlie? Like go for a ride and if yer can light yer boot when yer get back, there's a leak somewhere.

I'll never forget the day the two highway patrol cops suddenly start to back away from my bike when they see petrol pouring onto the hot right hand header pipe creating a cloud of white vapour.
Ah, back in the days before I repaired my carby seats.
Still gave me a speeding ticket for $227!