Stuck Pilot Screw, Got any Ideas?

[Chaharly]

Ok so I had it centered on the pilot screw until I took the head out. Now do I have to re center it on the stem of the pilot screw and drill into that?

 

I just figured as soon as I got the head off the rest would follow

[Marcarl]

Seeing as you drilled the head off, the point of the drill bit you used will leave a centering dimple in the remainder. Now go slow, using first a small bit and then ever larger. Don't jumps sizes and make sure they are sharp. Take your time to make sure you are going straight is also important. It'll work, just don't push it.

[flyday58]

I ended up getting a carb body and pilot screw from smithplace2004 on ebay. Turns out he was local so went for a visit. He was able to turn taking apart trashed carbs into a full-time job, he's got so much stuff. Mine was the #2 carb body but I think he still has the other three if you want to get up and running again. I've still got the old one with the stuck screw for a day when I've got time to fool with it.

[dingy]

Seeing as you drilled the head off, the point of the drill bit you used will leave a centering dimple in the remainder. Now go slow, using first a small bit and then ever larger. Don't jumps sizes and make sure they are sharp. Take your time to make sure you are going straight is also important. It'll work, just don't push it.

 

I just checked a bare carb body, and the largest bit that will fit in hole is a 1/4". This is taking into account the fractional, letter & numeral size drills. Very common size.

 

This is one needed to make initial dimple in stuck screw.

 

Once drill bit contacts top of screw, you need to drill initial 'dimple' hole about a 1/16th of an inch (0.062) deeper. This is so drill point reaches past screwdriver slot in screw and can contact center of screw body below screwdriver slot. If you look down screw hole with light after drilling, you should see shiny brass at center of screw. If not, smaller drill bit for secondary cuts will not have the needed dimple in center and will drift off center.

 

Body of screw head is slightly over 1/4" long.

 

Gary

Edited March 29, 2015 by dingy

[Chaharly]

I just checked a bare carb body, and the largest bit that will fit in hole is a 1/4". This is taking into account the fractional, letter & numeral size drills. Very common size.

 

This is one needed to make initial dimple in stuck screw.

 

Once drill bit contacts top of screw, you need to drill initial 'dimple' hole about a 1/16th of an inch (0.062) deeper. This is so drill point reaches past screwdriver slot in screw and can contact center of screw body below screwdriver slot. If you look down screw hole with light after drilling, you should see shiny brass at center of screw. If not, smaller drill bit for secondary cuts will not have the needed dimple in center and will drift off center.

 

Body of screw head is slightly over 1/4" long.

 

Gary

 

I guess where my problem is is that the threaded part of the jet is gone. I should just be able to pull out the rest of it right?

[dingy]

How have you came to the conclusion that the threaded part is gone?

 

Is there any of the needle protruding into the bore of carb? If there is needle protruding, and you are sure threaded portion is missing, then needle should push back, there is an O-ring and washer at bottom of hole also. I find the assumption that threaded portion is missing somewhat implausible though.

 

Do you have a set of calipers that are capable of a depth reading. If you can post how far into needle bore you can probe, I can measure same with carbs I have, and get an idea of what is left in hole. If your caliper doesn't have depth capability, insert something in hole, like a drill bit and measure how far it can go in, need a somewhat accurate measurement, using a tape measure is at low end of 'accurate' for stuff like this, but if is what you have, use it.

 

Measuring bare carb body I have, threads start at 1.010" below face.

 

Which carb is it that is fubar'd. I may have a spare.

 

Gary

[Chaharly]

How have you came to the conclusion that the threaded part is gone?

 

Is there any of the needle protruding into the bore of carb? If there is needle protruding, and you are sure threaded portion is missing, then needle should push back, there is an O-ring and washer at bottom of hole also. I find the assumption that threaded portion is missing somewhat implausible though.

 

Do you have a set of calipers that are capable of a depth reading. If you can post how far into needle bore you can probe, I can measure same with carbs I have, and get an idea of what is left in hole. If your caliper doesn't have depth capability, insert something in hole, like a drill bit and measure how far it can go in, need a somewhat accurate measurement, using a tape measure is at low end of 'accurate' for stuff like this, but if is what you have, use it.

 

Measuring bare carb body I have, threads start at 1.010" below face.

 

Which carb is it that is fubar'd. I may have a spare.

 

Gary

 

I can do that right away tomorrow. I tried pulling the jet screw out by doing only so far into it and tapping a torx bit into it. I drilled too far and managed to pull the threads out. So I'm pretty sure there is no head on the screw anymore

[scuff]

Bill,

 

Your profile shows you are an engineer, what field of engineering?

 

Gary

That made me LAUGH !!!!!!!!! Impact driver on brass AF screw !!!!!! that's sum funny stuff

[Chaharly]

I can do that right away tomorrow. I tried pulling the jet screw out by doing only so far into it and tapping a torx bit into it. I drilled too far and managed to pull the threads out. So I'm pretty sure there is no head on the screw anymore

 

And its the number 3 back right

[BlueSky]

That made me LAUGH !!!!!!!!! Impact driver on brass AF screw !!!!!! that's sum funny stuff

 

I still believe that the judicious use of an impact wrench or impact screwdriver if you could get a tip small enough to reach the pilot screw would loosen it to where a regular screwdriver would remove it. Drilling it out comes with risks too.

 

It's sad but every forum has some guys who try to make themselves feel superior by putting other people down.

 

By the way when I retired in 2013, my inferior engineering skills had enabled me to make more than a quarter million dollars a year. I'm sure a couple of genius's like you and Dingy are making much more? Right?

[Chaharly]

I still believe that the judicious use of an impact wrench or impact screwdriver if you could get a tip small enough to reach the pilot screw would loosen it to where a regular screwdriver would remove it. Drilling it out comes with risks too.

 

It's sad but every forum has some guys who try to make themselves feel superior by putting other people down.

 

By the way when I retired in 2013, my inferior engineering skills had enabled me to make more than a quarter million dollars a year. I'm sure a couple of genius's like you and Dingy are making much more? Right?

 

Lol I agree with you on the impact driver thing, I think those threads are tougher than we give them credit for. I wouldve tried an impact driver but I already buggered up the head too bad. When I tried the torx bit it actually worked pretty well and I HAD to hit on it pretty hard with my LFH (little friggin hammer). Now I'm going to try an easy out since I got the head, or at least most of it out.

 

I think these guys just get a nightmarish mental image of me pounding on the bad boy with my BFH And ruining a perfectly good carb body! They're just trying to help just like you and I really appreciate the help you guys have ALL given to me!

[scuff]

I still believe that the judicious use of an impact wrench or impact screwdriver if you could get a tip small enough to reach the pilot screw would loosen it to where a regular screwdriver would remove it. Drilling it out comes with risks too.

 

It's sad but every forum has some guys who try to make themselves feel superior by putting other people down.

 

By the way when I retired in 2013, my inferior engineering skills had enabled me to make more than a quarter million dollars a year. I'm sure a couple of genius's like you and Dingy are making much more? Right?

OK I'm sorry didn't mean to make you feel bad, didn't mean to make this into an argument about how much money ppl make, hope you get your problem fixed.

[Du-Rron]

I still believe that the judicious use of an impact wrench or impact screwdriver if you could get a tip small enough to reach the pilot screw would loosen it to where a regular screwdriver would remove it. Drilling it out comes with risks too.

 

It's sad but every forum has some guys who try to make themselves feel superior by putting other people down.

 

By the way when I retired in 2013, my inferior engineering skills had enabled me to make more than a quarter million dollars a year. I'm sure a couple of genius's like you and Dingy are making much more? Right?

 

Bluesky... Nothing bad directed your way when I was replying to @videoarizona. I am a goofball and I was just making fun of a mental thought I had while thinking of @Chaharly pounding away on the carbs with a drilling hammer. Kinda like thinking about Watch Repair using a claw hammer. Sometimes... ok well most of the time... my stuff is just funny to me. Please accept my apologies and please ignore me as I don't mean any harm.

[Brenner]

And its the number 3 back right

 

 

Dang!! Same one that gave me trouble on my rebuild. I got lucky and stretched the threads and with a little spray I walked the screw out. That long bore is an awkward place to work in. I feel for you.

[BlueSky]

Bluesky... Nothing bad directed your way when I was replying to @videoarizona. I am a goofball and I was just making fun of a mental thought I had while thinking of @Chaharly pounding away on the carbs with a drilling hammer. Kinda like thinking about Watch Repair using a claw hammer. Sometimes... ok well most of the time... my stuff is just funny to me. Please accept my apologies and please ignore me as I don't mean any harm.

 

Du-Rron, I enjoyed your posts. Keep them coming!

[venturesome]

I still believe that the judicious use of an impact wrench or impact screwdriver if you could get a tip small enough to reach the pilot screw would loosen it to where a regular screwdriver would remove it. Drilling it out comes with risks too.

 

It's sad but every forum has some guys who try to make themselves feel superior by putting other people down.

 

By the way when I retired in 2013, my inferior engineering skills had enabled me to make more than a quarter million dollars a year. I'm sure a couple of genius's like you and Dingy are making much more? Right?

 

thou doth protest too much

Overly insistent about something, to the point where the opposite is most likely true.

 

Lighten up Bluesky... A good sense of humor helps

[dingy]

As long as they are JIS screwdrivers...that would work to.

 

As far as I am aware, JIS (Japanese Industrial Standard) screwdrivers pertain to what we call Phillips head. The pilot screw has a flat blade type of slot.

 

The Phillips head was designed to cam out from engagement with the screw to prevent over tightening. This feature is great on an assembly line, but a pain in the buttocks when used for dis-assembly.

 

Quote from Wikipedia

 

"The rounded, tapered slots of the Phillips head were deliberately designed for the screwdriver to "cam out" (pop out) of the screw head recess under high torque on high-speed factory assembly lines.^[6] This prevents stripping damage to the screw threads, at the expense of possible damage to the recess in the screw head. Modern torque-limiting power driver tools for professional use eliminate overtorquing damage much more reliably. Market inertia and ignorance of the design's historical intent have led to widespread misapplication of Phillips head fasteners in applications where cam-out is not desirable. Some Phillips head screwdrivers have been manufactured with hardened "anti-cam-out" (ACO) grooves in an attempt to defeat this designed-in behavior.^[7] See torx head screw. "

 

Full text of above at http://en.wikipedia.org/wiki/Screwdriver

 

Gary

[BlueSky]

 

 

This coupled with the other crap you have directed my way this week,

Semper Fi,

 

Gary

 

I have no problem with anybody disagreeing with me. We all are tossing out ideas to hopefully help (and entertain) the thread starter. But, when you question my engineering background because you disagree with me, that's insulting. I answered that question honestly and straightforward. Scuff thought it was pretty funny that you would question my engineering background because of what I suggested.

 

I have no idea what posts you could be talking about. I would appreciate if you would direct me to the posts that you consider other crap directed your way this week. If I have unintentionally offended you, I have no qualms about apologizing for that. Help me understand this.

Bill

[dingy]

Bill,

 

Your profile shows you are an engineer, what field of engineering?

 

Gary

 

The above quote is what I posted, maybe I should have used smaller words. Since your profile listed your occupation as an Engineer, I was curious, at that point, I was still trying to be cordial.

 

I have over the decades worked with many different kinds of engineers, from aviation, to civil. Most engineers aren't know for there charming personalities, mine included. We tend to be introverts.

 

Prior incident was accusations you made here & on Facebook regarding the 88 Venture I recently purchased, Short term memory issues also?

 

Post #18 from below link.

 

http://www.venturerider.org/forum/showthread.php?99841-Remember-that-nasty-looking-700-dollar-Venture-Bob-posted-up-This-aint-it!!&p=900028#post900028

 

Gary

[BlueSky]

The above quote is what I posted, maybe I should have used smaller words. Since your profile listed your occupation as an Engineer, I was curious, at that point, I was still trying to be cordial.

 

I have over the decades worked with many different kinds of engineers, from aviation, to civil. Most engineers aren't know for there charming personalities, mine included. We tend to be introverts.

 

Prior incident was accusations you made here & on Facebook regarding the 88 Venture I recently purchased, Short term memory issues also?

 

Post #18 from below link.

 

http://www.venturerider.org/forum/showthread.php?99841-Remember-that-nasty-looking-700-dollar-Venture-Bob-posted-up-This-aint-it!!&p=900028#post900028

 

Gary

 

I didn't intend any offense to you on that post #18 for sure. I apologize if you took it that way. Puc didn't want the bike or he wouldn't have posted the link.

 

I don't have a facebook account so I don't know what you are talking about there. Perhaps you have me confused with another Bill.

[dingy]

Well then I will apologize, I thought it was you on Face Book, a few hours before you made above post, someone I thought was you was reaming me for buying bike out from under cowpuc. Not being able to relate FaceBook name to user name here has bit me in buttocks. My bad.

 

I am not good about getting pushed into a corner. Been attending R-Fator training that deals with this very type behavior.

 

Gary

[BlueSky]

Well then I will apologize, I thought it was you on Face Book, a few hours before you made above post, someone I thought was you was reaming me for buying bike out from under cowpuc. Not being able to relate FaceBook name to user name here has bit me in buttocks. My bad.

 

I am not good about getting pushed into a corner. Been attending R-Fator training that deals with this very type behavior.

 

Gary

 

Thanks Gary, In the future I will try to be more careful of how my posts will be interpreted. I'm gonna have to join Facebook. Seems everyone but me has an account. My adult daughter doesn't communicate with me much because I don't have an account! Ha!

[Flyinfool]

OK, Time to exchange and get back to the Pilot screw.

[videoarizona]

As far as I am aware, JIS (Japanese Industrial Standard) screwdrivers pertain to what we call Phillips head. The pilot screw has a flat blade type of slot.

The Phillips head was designed to cam out from engagement with the screw to prevent over tightening.

Gary

 

Hi Gary, My understanding is that it's a Phillips head that IS designed NOT to cam out. I have found the JIS screwdrivers do work better than SAE Phillips units...with far less stripping of the screw head. I do believe we are saying the same thing from the other side of the discussion.

 

Didn't know about the pilot head being a flat blade design....I haven't been down in there...yet! My bad!

david

[dingy]

I had just came back to post that very same thing. Actually, I am surprised I haven't got this thread deleted with my hissy fit.

 

And Charley was supposed to post some measurements, so we could help figure out what he done did to carb.

 

Gary