Martin 75 with Carter N Carb with broken low speed needle

[Buccaneer]

I succsessfully swapped out the old cracked up Wico coils
on the Martin with OMC universal, have good spark,
and was whistling Dixie until I moved on to the carb.
It appears that as some point the low speed needle snapped
off almost flush with the carb body and a screwdriver
slot was sawed into it.
Needless to say, I can’t budge it and now the slot in
the brass needle is beyond all hope.
I could…..
A. Hope that it’s adjusted okay and forget about it.
B. Find a different carb.
C. Try to remove the old needle.

Pretending that this was the last Carter N carb in the world,
what way would you try to remove the needle?
Drill with a left hand drill bit?
Drill and easy-out?
Other?

Photos of carb with broken needle, and of other Martin carb
with what I presume said needle is suppose to look like!
Thanks for any ideas.

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Prepare to be boarded!

[amuller]

I think it would be less confusing if you call the problematic piece the "needle" not the "jet."

Comparing the needle in the lower carb pictured can probably tell you how deep you would need to drill. At this point I would suspect the best alternative would be to drill out the needle to below the threads, and enlarge the hole as much as you can without drilling into the carb body. At that point the remains of the needle will hopefully fall out, and you can pick out residue and retap the threads. If you have access to left handed drill bits it would make sense to use them, as at some point the bit might catch and bring the remains out. I’ve never had much luck with EZouts but some people swear by them. this is a job that would be much easier with a mill and some small end mills, but should be doable on a drill press. Since you will still need another needle it might make sense to look around for another carb. (but, carbs often have subtle variations specific to the application…..)

[outboard315]

The good news is that it is a soft material with a softer screw. The better news is that I personally know it is not the last one on earth. If it is corroded in there then your chances of removing it dwindle.

[Buccaneer]

Wonder if I could make a tiny chisel, try to cut the slot deeper,
heat the carb gently around the needle, and try to unscrew ?

Prepare to be boarded!

[amuller]

Or you could use a cutting disk in a Dremel or a die grinder to make a slot. I don’t think It would do too much harm to slot the carb body a bit. But I’m thinking that if the needle was corroded in or otherwise stuck hard enough to twist off, your chances of getting it out aren’t too good. You could slot it, soak it with the acetone/ATF mix for a few days, and then heat it gently and maybe it would come out.

[Buccaneer]

Good tips. Seen something similar on YouTube where a guy
drilled into a brass jet a ways, then tapped a hexed Allen wrench
into the hole to turn it out with.

Prepare to be boarded!

[jerry]

Hey…I have several Martin carbs laying around…maybe one for a "75" as well…if you haven’t solved your problem in a few days, send an email to me…my number is in the master book…I’ll look for one for you…no guarantees but it’s worth a check. Got 3 "75’s" on the rack and don’t plan to restore another just yet…Jerry

[Buccaneer]

Thanks for the tips, and Jerry for the offer. I’ll play around
with it today and see what happens.

Prepare to be boarded!

[Buccaneer]

Success! I drilled a small hole in the broken needle about 3/8" deep.
Then found a hexed Allen wrench slightly bigger than the hole and
tapped it down. Heated up the carb body with a propane torch
for a while and the needle unscrewed !
Having no new needle, I decided to fix the old one. Found some
small brass round stock, drilled the same size hole in it as the broken
part, did a little machining to make a shoulder for the spring to ride on,
then cut off the Allen wrench the correct length, put a little epoxy
in the holes, and joined the two halves together. Seems to work good!

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[fisherman6]

Cool! Nice job Buc. Hopefully that epoxy holds. Looks like a good fix.
-Ben

OldJohnnyRude on YouTube

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