Anyone use screw extractor to remove stripped pilot screws?

[Nessism]

Got two stripped pilot screws and would like to remove them without cutting into the carb body with a cutoff disc per common practice. Have any of you guys had success drilling the screw and working it out with a screw extractor? The pilot screws are pretty far up so they don't have that far to go. Even if the screw extractor busted it wouldn't be a big deal since I could always use the dremel then.

[tom203]

Small screw extractors in this size range have repeatly failed me- just too brittle. Get some decent left hand drill bits, align stuff up i carefully and hsve a go.

[Kiwi Canuck]

Ed, have you used heat yet?

I've had a few pilot screws get pretty stuck and managed to get them out using heat (a lot more than you think) and a near new 4MM Wera flat blade screwdriver and managed to get it to bite and they came out.

https://www.amazon.ca/Wera-05110005002-Kraftform-Slotted-Screwdriver/dp/B00365EXWW/ref=sr_1_3/168-9100020-5802020?ie=UTF8&qid=1474058869&sr=8-3&keywords=wera%2B4mm&th=1

The only type of extractor I've used with success is the Grabit with a left hand drill on one end and a screw extractor on the other end, but they are too fat to fit down the hole to get at the pilot screw.

Take your chances with the conventional type.

Another option maybe to drill out the pilot a bit to fit torx head screwdriver and drive it into the top of the pilot and hope it bites enough to get it out. (with heat of course)

Good luck.

David

[jabcb]

Wasn’t a pilot air screw, but I recently had a buggered up two-stroke pilot jet to remove.
Got a HarborFreight extractor set just a few bucks.
Used the smallest set: drilled a hole with the 5/64” bit & used the #1 extractor turned with a crescent wrench.
Turned the crescent wrench slowly so it could dig in without snapping off or acting like a drill bit.

[JTGS850GL]

Don't use an EZ-Out. If you do you'll probably be looking for a new carb body. Once they break off it's dam near impossible to remove them. Heat is the answer if you have any slot left. Don't be cautious on the heat. I use PB blaster and lots of heat BEFORE I try to turn them. If you can't/wont cut the tower, then it may be possible to drill a hole down the pilot screw and force a Torx bit into the hole to get a bite on it. I've never actually tried it but it's a better option then using an EZ-OUT. I know it works on seriously buggered up jet. Those screws can be a real PITA. I think the factory used some form of locktite to keep them in place. The heat seems to melt it and allow the screws to turn. If you can get it to start to turn don't try to turn them all the way out. If it starts to bind then go back and fourth and inch it out. Add more heat if you have to. Wont hurt anything. Nothing in that area will melt.

[Nessism]

The screw turned fine at the bottom but near the top, where the threads were exposed, there was corrosion and the screw bound up and I wound up damaging the slot. I've got some LH drill bits so maybe I'll try drilling into the screw and using the torx bit trick. If that fails I'll just keep drilling. I busted a chunk out of one of the pilot towers trying to remove the plug. Had issues with a second plug and wound up having to drill it out. Corrosion is a bugger.

[chuck hahn]

Is there a tiny Dremel bit that may potentially allow you to route a new slot ( to some extent) and then allow you to use a screwdriver again??

[geol]

Dremel tools won't get it done. The smallest screw extractor is an EZ out. Problem is, the tip will want to break off and then if you try drilling, even with a carbide drill bit... it will slip and the hole will be off center. The small square extractors don't break easily and are best. The HF extractor mentioned is as bad, if not worse for breaking off than the EZ Out but the EZ has the most bite of any.

Suggest this. Use a fairly sharp punch to make a hole in the middle of screw. A 3/16" drill bit seems to be about right. Tap the smallest EZ-Out so that the screw breaks loose a tad. I guess I will say I have had the most success with the EZ-out. Fill the well with PB Blaster or Kroil. Use a propane torch and heat the well; as has been said, longer then you would think. Hopefully you have the carb in a vise and the diaphragm and choke plunger removed... After heating, tap some more (not real hard) with that hammer and see if the screw moves a tad using the EZ-Out. Don't force. If it doesn't, try the PB Blaster and heat again for a bit longer and try again.

The reason they stick is kind of unique to Suzuki BS models. Seems the little guy who glued those plugs over the screws was given a BIG container of adhesive. There may be a little corrosion but generally it is the glue; especially when you can turn the screw a turn or so and then it sticks. I have never figured out a great way of reslotting the original inside the well and hate whacking the well with a Dremel cut off wheel. If the screw is stuck and has the original slot, same deal with PB Blaster and HEAT! And use the correct size screwdriver else it will slip and strip as I suppose most have already learned.

If you are desperate, take the carb body to a machine shop. They can jig it and use a small drill press bit. The screw is either M5 or M6 (can't recall off the top of my head) but has .5 pitch so there won't be an insert in your future if the thread is ruined.

[hikermikem]

Hey Ed,

I've removed several stuck pilots (and I mean STUCK!) using the technique JTGS850GL described... I drill a hole in the offending pilot and then hammer a torx bit down that soft brass hole. It grabs very well into the brass & is less likely to snap like those screw extractor/EZ out bits - use the largest bit you can slam down the hole. I use a Torx screw driver that has flats in the shaft near the handle where I simply put a wrench on to get lots of turning torque.

Additionally, I use a 50/50 mix of acetone & ATF as penetrating oil (works extremely well) and heat the outside of the pilot area using a propane torch. The acetone/ATF mix doesn't really ignite (much to my surprise) but I have a bucket of water & an extingusher standing by just in case.

Use the penetrating oil mix liberally & apply the heat liberally as well - I go through a few heat cycles using the oil when it's HOT. Then heat it up & try turning your home-made bit extractor - I've never had this fail & have not damaged the carb body either.

Once removed I retap the hole & it's good to go!

Good Luck

[jabcb]

Sorry for the bad advise — these four strokes are very different that what I work on as an amateur/home mechanic.

[Nessism]

Drilled into the old screw and used the torx bit trick. First one came out easy. Second one, no dice. Had to drill out the entire screw and now there is a shell of brass still stuck down the hole. That's a first for my experiences. Typically once the old screw gets thin it's spins out but not this one. I'm going to have to buy a tap now. Not too thrilled by that since the cheapest 6mm x .5 tap I've found is $10, and it looks like a China cheapie. If anyone knows where I can get a good quality tap for a reasonable price please chime in.

[chuck hahn]

Can you use a fine pick and collapse the shell into itself and use tweezers to turn and extract it??? If you can get it to collapse into itself add some oil as you go to soak into the threads. usually if it gets imploded a bit they will start to loosen up.

[Kiwi Canuck]

Drilled into the old screw and used the torx bit trick. First one came out easy. Second one, no dice. Had to drill out the entire screw and now there is a shell of brass still stuck down the hole. That's a first for my experiences. Typically once the old screw gets thin it's spins out but not this one. I'm going to have to buy a tap now. Not too thrilled by that since the cheapest 6mm x .5 tap I've found is $10, and it looks like a China cheapie. If anyone knows where I can get a good quality tap for a reasonable price please chime in.

Quality but not cheap.

http://www.mcmaster.com/#standard-taps/=147a8q1

Click on general purpose taps then select metric and 6mm to narrow down the options.


Not sure what else you can do other than soak it for a day or so and keep hitting it with heat, and then drop it in cold water as well, sometimes the shock will break the bond.

[AMK]

Can you use a fine pick and collapse the shell into itself and use tweezers to turn and extract it??? If you can get it to collapse into itself add some oil as you go to soak into the threads. usually if it gets imploded a bit they will start to loosen up.

This is good advice.

[chuck hahn]

I use the drill the center out and collapse the shell method on exhaust flange bolts all the time with very good success. Run a tap in to refresh the threads and all is usually good to go.