Topic: Stripped Screw Question

[Cain74]

I am trying to remove the gear shift side plate and the screw head stripped.  I first tried using a phillips head on it because I didn't know any better and then found out about JIS heads.   I bought the correct JIS Screwdriver but it still stripped.  It is in there good and tight.  I also noticed that someone tried getting the counter shaft bearing holder off and started to mangle the head.  Any advice?  The bike is a 1973 750 if that helps any.

[72500john]

try an impact driver,the kind you hit with a hammer with a little valve grinding compound on the bit.  if too far gone use a small sharp chisel and givem a whack to loosen. of course in the loosening direction.

[Markcb750]

Left handed drill from Harbor freight  will often screw the damaged panhead out;,or a std drill about 6mm dia.  drill off the head, they are soft so it is easy to drill, then remove the stud after you have the cover off.

(I say HF because everyone else seems to think the LH drills are worth 5 times a std drill...)

If I can reach the head sometimes I can use a dremmel tool with a cutting blade and cut a slot across the head and try to use std screw driver.

Get an impact driver...

[Cain74]

Wow that was quick.  I'll try the impact driver.  Does anyone know where to buy replacement screws?

[Stev-o]

Might be a good time to upgrade to socket head screws on the engine covers. Kits are available on eBay 

[72500john]

one of my local cycle shops keeps them in stock in diffrent lengths. had to cut mine for lenght. check around your area.

[camelman]

Replacement screws are available at Ace Hardware stores for pennies each. They are called "cheese head" screws.

C-man

[cameron]

+1 for drilling the head off. Regular RH drill bit is fine.

www.stainlesscycle.com for all your fastener needs.

[lrutt]

The hammer and center puch trick works often. Or...take a dremel and create a nice wide deep slot and use a straight edge bit on your impact wrench. Those both have always worked for me.

[stereosilence]

If the screw is pan head, I have had luck clamping it with vise grips to torque it off. I have also used an EasyOut before with success. They are usually $5 but I got a really tough screw out.

Good luck.

[Cain74]

I tried the impact driver and that didn't work.  I ended up drilling them out with the left handed drill bits  worked great.  Just have to go find replacements. 

[greenjeans]

Honda has all the bolts you need (although they will be way over-priced)  Most bolt supply places (Fastenal etc) can get them.   
Go here:  http://www.westernhillshondayamaha.com/fiche_select.asp

It will tell you the size, length and number of the screws that you need - speeds up the process when yo go looking for bolts.

[MCRider]

The thing to remember is 99 out of 100, the part that's stuck is the underside of the screw head stuck to the cover. So a standard drill as mentioned, carefully drill off the head of the screw, the cover comes off, and the remaining shaft threads out easily. Usually.

It is my contention that the 6mm screw is not JIS or it would have the JIS identifier dot on it. Look at the 5mm and smaller screws, which are JIS, and you'll see the dot. Like the one that holds the tach cable in.

JIS screwdrivers work fine in both ISO and JIS heads. So its easy for an owner of a JIS tool to say the screws are JIS. But if the slots are healthy, the ISO standard #3 Phillips works fine. If you've already degraded the slots, all bets are off.

ISO screwdrivers only work in ISO screws and shouldn't be used on the JIS if possible. But since there are so few of them and usually in a non-critical role, what the heck?

On the hammer and punch method, i use a tiny chisel. Set it at an angle on the head of the screw and tap it in the counterclockwise direction. usually works. But some screws are in a recess and can't get the chisel in there.

[cameron]

HEX HEX! Its Sexy.

(also a tiny suggestion for the next time you are in there)

[lucky]

The thing to remember is 99 out of 100, the part that's stuck is the underside of the screw head stuck to the cover. So a standard drill as mentioned, carefully drill off the head of the screw, the cover comes off, and the remaining shaft threads out easily. Usually.

It is my contention that the 6mm screw is not JIS or it would have the JIS identifier dot on it. Look at the 5mm and smaller screws, which are JIS, and you'll see the dot. Like the one that holds the tach cable in.

JIS screwdrivers work fine in both ISO and JIS heads. So its easy for an owner of a JIS tool to say the screws are JIS. But if the slots are healthy, the ISO standard #3 Phillips works fine. If you've already degraded the slots, all bets are off.

ISO screwdrivers only work in ISO screws and shouldn't be used on the JIS if possible. But since there are so few of them and usually in a non-critical role, what the heck?

On the hammer and punch method, i use a tiny chisel. Set it at an angle on the head of the screw and tap it in the counterclockwise direction. usually works. But some screws are in a recess and can't get the chisel in there.

This information is incorrect.
IJS stands for Japanese International Standard.
OSO is International Standards organization.

About 1964 Honda switched to ISO threads.
Part of the reason was that people were having fires on motorcycles from fuel leaks caused by people using modern metric thread screws in the older IJS manufactured bikes carburators.

If you look at an carb on a Honda or other Japanese bike, you will se a small punch mark on the head of the screw. This is an ISO modern metric screw.
Is is almost impossible to find a IJS screw nowdays. They are not marked.


As far as removing metric screws always use the correct size phillips screw driver or impact bit.
THE cylinder head cover on most CB750's is a #3 phillips screw NOT a number#2.

If you use the wrong size screw driver the screw will be ruined.
Always use the largest size phillips bit that will fit in the screw head.
Always give a small tap on the screw head before trying to remove the screw.
Do not put the screw driver in the head of the screw driver and tap the screwdriver handle because the plastic handle absorbs the shock and does not loosen the screw.
Hit the head of the screw with a small ball peen hammer directly.

[MCRider]

Lucky: Why do you insist on making broad unqualified statements? Not everything in my post is wrong.

Yes its true the threads were standardized from JIS to ISO (not OSO). We are talking about the drive head, which in many cases remained JIS and requires a JIS screwdriver to be driven properly. These screws are still being used to this day, usually "miniature" in cameras, RC toys etc. True, not in modern motorcycles, I think.

I may have the purpose of the Dot wrong. I'm beginnning to think so. But the Dot will give someone a clue that the screw was once a JIS, the dot indicating the thread has been standardized to USO. However the drive head may or may not be ISO.   

I don't mind discussing these issues.

[Markcb750]

This is a good fit.

I use the Mallet to seat the screw driver in the cleaned out "X" and to break it free (perhaps, if I'm lucky) by smacking the handle into the screw several times before I attempt to remove the screw.

I have found I can keep firmer pressure on the driver if I lean into the driver and use the adjustable to apply torque.  The key is firm pressure along the screw axis with a proper fitting driver.  JIS, ISO, ANSI; who the hell knows.  For me it took a trip to the Home Depot with a screw in hand to find this Cresent #3

Even with this method sometimes the head gets drilled off after I try my 35 year old made in USA Craftsman impact driver. 

The '67 cb450 I am restoring has many that I have or will need to drill out because the impact driver stripped out the head..This is part of the charm.