Topic: Stripped Screws on My CB750

[chickenman_26]

Stripping a screw is a lot different than messing up brain surgery 

It was an analogy - one you didn't find relevant.  Good luck.

[martin99]

Full marks for 'fessing up is what I say. Back in the '80's I used to work in a main Ford franchise in the spares department. You'd often get apprentices coming up holding some part or other, proclaiming 'it broke' rather than saying 'I broke it'. Used to drive me f@*king nuts, still does.

I had to have two tyres replaced on my car not so long ago, and some gorilla proceeded to remove the locking wheel nuts with an air wrench, stuffing up both sides. Then spent twenty minutes smacking the crap out of my hubs to remove the mangled wheelnuts, and tried to charge me for the labor! I saw red, and I must have frightened him when I got going 'cos not only did he drop the labor charge, I got a discount off the tyres too! Some people just weren't meant to wield a wrench.

I've made plenty of mistakes in my time, the trick is to learn from them so they don't happen again. You'll be ok, you're starting out with the right attitude.

[AintNoEasyWay]

As far as fessing up goes, it's funny to me the guys you all are mentioning who won't take credit for errors. Are they too dumb to realize that an experienced mechanic can usually tell what really happened & who's at fault?

One piece of advice I can throw in here is that screw extractors are by no means the end-all be-all of getting screws out. Usually there's a reason that the screw/bold won't come out. In this case it's a stripped head; but often it's buggered threads, corrosion or the like that's keeping a screw from coming out. In those cases, all the twisting in the world isn't going to get it out - you'll likely end up snapping off the extractor, which is usually hardened and not easy to drill. So use extractors lightly, knowing that if it doesn't come out relatively easy then there's something else at play.

Glad you got the one out - good luck with the other!

Thanks a lot Tugboat. That's great advice to follow from here on out.

[lucky]

Every mechanic has broken something or stripped a screw but they all learned how to avoid getting into that situation. they got the right tools to do the job as soon as they suspected there could be trouble.

But when working on vintage anything, you are always aware that if something breaks there may be hell to pay to get it back in order. So you take it easy from the start.

Some of us learned when we were 18, some of us did not learn until we were 40, but it is the same lesson. We always can benefit from a more experienced mechanic.

[AintNoEasyWay]

Lucky, very good points. Thank you.

Thanks to all who had some input on the thread. I drilled off the head of the screw down in the throttle slide, popped it off & unscrewed the remaining thread with small needle nose. Worked liked a charm, as you guys recommended.

I also used the dremel technique for the screw on top of the link arm assembly. Pictures are below. It's a huge relief & now I can move on to cleaning the rest of the carbs. Also, my vessel JIS driver came in so I'll be using that from now on. Thanks again guys!

[Jonm99]

I recently purchased a 1977 cb750 k and had the same problem with one of my carbs, stripped screw on the arm link. Anyone know where to source these screws or an alternative? I was only able to find the entire arm link set, which is a bit of an overkill...

[Keith]

I hate philips head screws! Without constant downward pressure, the tools tends to ramp out of the fastener. On some fasteners, you can tap the handle of the screwdriver with a small hsmmer as you turn to keep it seated, a poor man's impact driver.

[jgger]

I'll just place this here.......

Pain is the catalyst that bonds a bad experience into wisdom!

That is an old proverb I just made up.

[Stev-o]

I hate philips head screws!

If you are referring to the screws on your Honda, they are not phillips, they are JIS.  Get a set of the JIS screwdrivers, the Impacta is a poor mans impact!

https://www.amazon.com/Vessel-Megadora-Impacta-P2x150-Screwdriver/dp/B003BGZ9CO

[ekpent]

 That was a Zombie thread brought back from 2013. Wonder how ole' Lucky is doing,see he was active about a year ago.

[Stev-o]

That was a Zombie thread brought back from 2013. Wonder how ole' Lucky is doing,see he was active about a year ago.

Almost hate to admit it, but I miss Lucky in an odd, weird way. 
Some of his posts were so off the wall they were entertaining. 

[CycleRanger]

I hate philips head screws!

If you are referring to the screws on your Honda, they are not phillips, they are JIS.  Get a set of the JIS screwdrivers, the Impacta is a poor mans impact!

https://www.amazon.com/Vessel-Megadora-Impacta-P2x150-Screwdriver/dp/B003BGZ9CO

Oooh, hey, I want one of those!

[Stev-o]

I hate philips head screws!

If you are referring to the screws on your Honda, they are not phillips, they are JIS.  Get a set of the JIS screwdrivers, the Impacta is a poor mans impact!

https://www.amazon.com/Vessel-Megadora-Impacta-P2x150-Screwdriver/dp/B003BGZ9CO

Oooh, hey, I want one of those!

Can't believe you don't have one.  I bought myself one for Xmas a couple years back. 

[CycleRanger]

Oooh, hey, I want one of those!

Can't believe you don't have one.  I bought myself one for Xmas a couple years back.

Well I guess I just now realized I need one! 

[Keith]

Yes, the Honda uses JIS fasteners; however, they are based on the Phillips patent, so are technically a Phillips type. These fasteners were designed to simplify assembly line production, that's the reason for the tapered sides. Without constant downward force when removing, the bit will have a tendency to ramp out, a worn or poorly fitting bit only makes matters worse. If the taper was eliminated, and the fasteners had straight sides, the amount of force that could be applied to the fastener could be nearly doubled. (Torx bit would be an example of this) While I'm on a rant, I hate Allen heads too! I don't understand why many German auto manufactuters use allen head fasteners when a hex head would suffice...because they're pretty? Did you ever notice the square drive on a ratchet, extension, or socket almost never strips..the bolt will snap or round off, or the socket will crack first. Still, in my opinion, Phillips fasteners are the worst choice of all. Observations from a retired 25+ year master auto technician.

[Stev-o]

While I'm on a rant, I hate Allen heads too!

Why?   I've never had a problem with them...

[calj737]

While I'm on a rant, I hate Allen heads too! I don't understand why many German auto manufactuters use allen head fasteners when a hex head would suffice...because they're pretty?

Because knuckleheads use 12-pt sockets on hex head fasteners and round off the corners, making them crap. With socket head cap screws, you can only use a hex drive tool. Actually, 12-pt heads are far stronger and damage less due to their significant increase in surface areas. But that's a different story...

Torx, E-Torx, and their derivatives wear far better and are damaged far less. Get accustomed to it; its the way of the world.

[Keith]

Many times, the allen head gets filled with dirt, rust, etc. especially on a vehicle exposed to harsh winters. A front wheel drive front axle would be a good example, especially if someone had buggered it up first. Or an exhaust system that's up against the firewall, with no room to drill it out without pulling the cylinder head. Or, under a timing cover up against the strut tower. I can see using an allen fastener in a recess, but few other places.

[jgger]

Nothing is totally stooped proof. One of my Mesicans at work was "fixing" his nail gun and didn't have the right size allen wrench.........so he pounded a Torx bit into it. Some of the things you see, just WOW!

[Stev-o]

I can see using an allen fastener in a recess, but few other places.

I think a stainless socket head screw looks fantastic on a polished aluminum engine cover, hard to beat that.

[calj737]

Many times, the allen head gets filled with dirt, rust, etc. especially on a vehicle exposed to harsh winters. A front wheel drive front axle would be a good example, especially if someone had buggered it up first. Or an exhaust system that's up against the firewall, with no room to drill it out without pulling the cylinder head. Or, under a timing cover up against the strut tower. I can see using an allen fastener in a recess, but few other places.

Well, quality stainless fasteners won't rust, but black oxide and zinc plated do. As for accumulated dirt and grime, ever hear of a car wash? Works really well at rinsing and cleaning the undercarriage of a car, especially after winter driving.

[Keith]

All true, but I'm coming from the perspective of a 40 to 60 hour per week professional trying to make a living, where most jobs pay a flat rate. A one hour job should take one hour... or less.  A car wash is great on your own vehicle, not so practical at a repair shop. One buggered up fastener can ruin your day. If anyone has been in that situation, you know where I'm coming from.

[jonda500]

Allen bolts are indeed a really neat choice for recessed holes and can work well when a hole is too close to a corner as they don't need much clearance beside them... but you wont find any allen bolts anywhere on my hondas!
John
One of my honda publications designates the screw heads as either plus or minus (+ or -)