Removing stuck carb Jets

[copeland3300]

I'm trying to find a good way to take out the 3/4 pilot jets that are fully stuck in my 80G carbs. Unfortunately they're in there good and I don't think they're coming out in good shape. I also need two new float needle valves, but I'm unsure which one I should be getting.

I saw in this thread that hbonser was having an issue as well. There were some suggestions of taking it out via a drill and a tap, a machine screw, etc, but I was still a little bit confused about what to actually do. I've also heard about using PB blaster to loosen things up or even boil outs where you remove everything that's not metal, soak the whole thing in gasoline overnight and light it on fire.

I feel like there has to be a better way to keep track of all this stuff rather than making a thread each time it comes up.

Additionally, adding some specifics on what parts each model carb uses would be great when we're trying to figure out what is supposed to go where.

Perhaps a sticky or a tech tip is in order?

[crazy steve]

The reason there's no tech tip for this is what's needed can vary so much; there's no hard-and-fast rule. All of these methods will work, some are obviously more work than others, but which method is best for you depends on how bad the jets are frozen in there. If the slots on the jets are still there, there's several methods that can be tried. Slots totally gone? Then the drill/tap or ez-out methods will probably be your choice. It is best if you can get the jets out with disturbing/damaging the OEM threads, but that's not always possible.

So, it all depends....

[copeland3300]

Well then can we detail those methods? For example, you mention the EZ out. I assume that's a screw extractor. Also how would you go about doing the sheet metal screw method?

[DGXSER]

I think if you read through the Carbs 101 tech tip, it does mention to use some type of PB Blaster or Liquid Wrench type product BEFORE you try to remove the jets. Let it soak for a day or so even.

As Steve suggested, trying to wrote an all inclusive methodology to this would be very difficult. The path to success varies by alot of conditions. And yes, screwing up the factory threads should be a last resort!!

Myself, I have used PB Blaster on pilot jets and then still buggered up the slots to the point I had to use an extractor, and usually that works. However, I had a set of parts carbs that were just horribly corroded and a complete mess. I tried that same technique on those and broke the extractor off in the jet. So it is not a one size fits all solution.

[copeland3300]

I suppose I might be making things a little more difficult for myself by trying to get it out. Perhaps I don't have to. This thread makes me think I might just leave it.

I'll soak it in carb cleaner overnight and then see what I'm working with.

[GLoweVA]

I be weary of leaving it in overnite. Carb cleaner can eat up the butterfly shaft seals.
I had to use an easyout like this one just a few weeks ago.



I used a very small drill bit to get the hole big enough for the easyout bit to grab.

my 2 cents, get that sucker outta there. Do it now, or do it later, at some point you're gonna want/need to get it out, so might as well do it now.
Then, when you put a new one in and the old ones back in their holes, you'll know 100% that they're good to go.

[crazy steve]

I'm not a fan of using ez-outs (AKA screw extractors) on these because if the extractor breaks off in the jet (and they can), it's extremely difficult to then drill it out (the next step) because the extractor metal is much harder than what it's stuck in. This will basically mean a trip to the machine shop ($$$) and there's still no guarantee that the body can be salvaged. A better choice IMO is to use a left-hand drill bit, hoping that the bit 'biting' into the jet will unscrew it. Applying some heat to the carb body to expand the casting will help; a larger soldering iron will work best here.

Personally, if there's no slot left on the jet, I'll just drill it out and retap the hole. The pilot jet thread is a 'standard' metric thread (5mm/.8 IIRC, but doublecheck that), so drilling it with the correct tapping bit and then running a tap in to restore the threads will usually fix these. You do need to be careful while doing this (I'd highly recommend using a drill press to drill it) to keep the hole straight.

[GLoweVA]

I've never seen a left threaded drill bit, but I'd agree that would probably be a better choice to start with.
If it doesn't come out with that bit, then at least you've already got a hole for the extractor.

[old_chopper]

With a little practice you can sharpen a regular drill bit in reverse and use it as a left hander, assuming one isn't readily available. It's a good method to get the stuck jets out.

[bikerphil]

Only problem is most home drill press don't run backward, you'd have to use a reversible hand drill with the left hand bits....

http://www.harborfreight.com/13-piec...set-95146.html

[copeland3300]

How about heat from a propane torch and left handed drill bits?

[crazy steve]

How about heat from a propane torch and left handed drill bits?

That will work, but you have to be careful not to get the carb body too hot. There's sealant in various places where they plugged ends of drilled passages and you don't want to destroy that. Plus you don't want to bake any 'gunk' inside the carb into place.

Phil brought up a good point about reversable drill presses. If you don't have one, drill the jet with a slightly smaller regular bit first in the press, then your hand-held drill will have a straight hole to follow.

[tarzan]

Brass is pretty soft.If you do have a drill press and it doesn't have reverse, you can turn it backwards by hand.You may have to drill it out a little first so the beginning of the hole is big enough for the flutes of the drill to grab the material.Then when you turn the spindle by hand while applying some pressure it should make the drill bite in.

Another way would be to drill the head of the jet off.You would use a drill a little bigger than the thread is on the jet.Just drill through the head gently, until the head comes loose.Then pull out the head out and the threaded part should then be easier to back out.

[CaptonZap]

I've never seen a left threaded drill bit, but I'd agree that would probably be a better choice to start with.
If it doesn't come out with that bit, then at least you've already got a hole for the extractor.

The tap drill size for the M5 X.8 is a #19 drill bit, which is .001 in larger than the metric tap drill, but hey, we're not holding the head on with it, so a loose fit won't hurt. MSC may sell single left hand number drills. If not, a right hander will have to do.
A word of advice, if I may.
Start off with a #30, or there abouts drill bit. Take the top covers off, and set the carb bank on the drill press table, upside down, after making sure that it is square with the spindle.
Drill down about a quarter inch, from where your drill bit contacted the jet, which should get you past the threaded portion of the jet. Look at a new jet to get the depth right. You want to drill just past the threads.
Blow out the chips, and go to a #25 drill. Do it again. Same depth.
DO NOT run the smaller drill bits in to far. There is a tapered seat at the bottom of the hole that the jet seats against, and if you drill to far with the smaller drills, you can screw that seat up.

Now you can drill with the #19 bit, and when you get past the threaded portion of the jet, you will hit the portion of the jet with the holes in it. At that point, the bit will spin the holey part, and will not want to drill any more, since it is spinning the holey part of the jet. Now you can turn the carbs over , (which is the way they normally set), and the holey part should fall out, as it's diameter is less than the #19 drill bit. You may need to tap the carb with a plastic screwdriver handle to jar the holey piece out
Then, a M5 X.8 tap will clean up the threads. You will want a plug tap, and then a bottoming tap, so as not to screw up the seat at the bottom of the hole by running the taps into it.

Good luck, and if you have any questions, ask.
CZ

[Cobia]

This worked for me

I got the tip from here also. First soak them good with PB Blaster... overnight.
The slot in mine was buggered up too, so I got a set of diamond "dentist sized" dremel bits. With and appropiate size bit I re-cut the screwdriver slot and made sure it was snug on the tip of the screwdriver bit. Then I heated the "column" where it lives and put pressure on it. It came out without much fuss. BTW - this was for the pilot jet.