Topic: Screws behind alternator cover stripped to hell!! ?

[robdrobd]

I have a cafe finned alternator cover that I was wanting to put on, but after popping off the stock cover, I found that the three screws underneath are so stripped that the insides of the screw heads are round. I was able to get one out with a extractor set, but the others are to bad. Am I going to damage any internals if drill them out. Any suggestions? Freakin' PO.

[754]

Get a left hand drill bit, 1/8 inch..probaly wind them right out..

[Alan F.]

If you drill just a little at a time, until the head comes off the screw and check often to make sure you haven't drilled too far and you should be OK.
I went thru this with a clutch cover screw, just be careful and check your progress OFTEN.
-Alan

[robdrobd]

If I drill the screws out will I have to re-tap or is there another way to attach the cover?

[hijynx]

if it's a phillips or hex socket (allen) head use a drill bit bigger than the threaded part of the fastener & smaller than the head. when the bit cuts the head off it will spin preventing the bit from cutting into the case. most of the time once the case is off i've been able to remove the rest of the screw by hand & if not you will have something to grab. if it doesn't budge use a heat gun on the case around the bolt - the aluminum will expand before the bolt does. if you haven't done this before drill a hole in a piece of wood, screw a fastener like you have with a nut on the back, tighten & drill away since you aren't drilling away on your engine case. once you have it figured out get the roached pieces out & put anti seize under the head of the new parts as well as on the threads. this will work with a standard (hex) haed bolt too but it's harder to center the bit.

[robdrobd]

Still can't get these bastards out. It doesn't seem like the drill bit is even working. I am using a standard drill bit. Do I need to use a cobalt bit or something?

[mwvachon]

Had the same problem on my CB500-K0. The alternator cover thread holes go all the way through the casing and corrosion sets in from the back side! What a b*tch! I ended up [VERY CAREFULLY, mind you] drilling out the screw completely. I used a drill bit that was just shy of the bolt diameter. You have to be very careful about keeping it square to the case. Afterward, I chased the hole with a tap [don't remember the exact size]. Turned out that the hole ended up being slightly skewed, but if I loosely started all 3 cover screws a few turns and then tightened them equally, it worked ok.

[7145cb650]

I had the same problem with my CB650. Took a Cut-Off wheel on a die grinder and cut slots in each screw so that I could use a regular screwdriver. Had to replace the screws but it was a quick fix.

[CB650 Wolf]

I just had the same problem when pulling my carbs apart for cleaning. I just grabbed some vice grips and put it on the head of the screw. After a couple of times it worked. Also if you can manage to get a little bite with a screwdriver then you might try some comet (scouring powder). It can help get a better grip on that screw.

[robdrobd]

I wish I could use vise grips, but the screws are behind the dyno cover and are countersunk into the aluminum.

[mystic_1]

Which screws are we talking about here, #17 that hold in the field coil, or #18 that hold in the stator?



You should only need to remove #17 but those drive in from the outside, not from inside as your post states.

You said,

It doesn't seem like the drill bit is even working.

So the bit isn't penetrating the screws?  You might need to just apply more pressure, the screws aren't any special alloy that requires special bits.  Maybe start with a smaller bit and drill pilot holes, then step up to the larger size to drill the heads off.  In any case go slowly so as to avoid mucking up the cover or the coils.

Best of luck
mystic_1

[75 honda]

I always have the best luck with using torx bits.  Find one that feels like it would fit and tap it in with a hammer.  Put the ratchet on it and it should come out.  I had this problem when I was splitting my cases.  My counter sunk phillips head screws were stripped so I tapped the torx bit onto it and it worked.  A few of them I actually used a drill bit to round it out and hammered an even bigger torx bit into the fresh drilled hole. 

[robdrobd]

It is the #17's that are stripped.

[MCRider]

I have a cafe finned alternator cover that I was wanting to put on, but after popping off the stock cover, I found that the three screws underneath are so stripped that the insides of the screw heads are round. I was able to get one out with a extractor set, but the others are to bad. Am I going to damage any internals if drill them out. Any suggestions? Freakin' PO.

When you say "popping off the stock cover"... there is no stock cover there. those 3 screws (#17s on diagram way below) are exposed in stock trim. On to your problem, if you drill the heads off, you won't be able to get the stubs out without removing the large dyno cover you are working on, held on by 10 screws or so, and letting that center magnet (#9 in the diagram) fall out. Then you can get the vicegrips on the stubs.

You got a problem there...

Try some of the other methods but once you attack it in earnest you will not be able to turn back.

I think you will have to remove the large cover proper, drill out the 17s, forst or second, get the electromagnet out where you can work on it. There may not be enough stubs to grab and you have to continus drilling.

Anything you can jam in like the torx to turn the screws backwards would be nice.

[robdrobd]

Now I feel like I've gone too far to turn back, but still only successfully removed one screw. One is so drilled out I can't believe the head is still on.

[MCRider]

Now I feel like I've gone too far to turn back, but still only successfully removed one screw. One is so drilled out I can't believe the head is still on.

AS i said once you get started...

Those screws have sealing washers on them as there is oil in that cover. Do as much damage as you can while the cover is on, but I'm thinking you'll have to take it off.

IIRC that involves taking the tranny cover off too as there is a wire from the alternator that threads through a passage in the tranny cover. Need a confirm on that. Both covers require gaskets.

[robdrobd]

There was not a washer on the one screw I was able to remove. Could this be the problem with them being stuck so badly?

[MCRider]

There was not a washer on the one screw I was able to remove. Could this be the problem with them being stuck so badly?

As you can see in the diagram, there is a washer #13 under screw #17, the ones you are working on. Since yours didn't have one, that's evidence to me someone has been there before you.

I'm thinking its a copper washer for sealing the oil, but I could be wrong. A washer nonetheless. The oil behind that cover is not under pressure and is a mist that is flung around by the spinning rotor. Then drains back into the sump.

The washer not being there should not bear directly on how hard it is to get those screws out. More likely it is evidence someone took them out and then replaced them with too much zeal. replacement should have involved some anti-seize compound (I always use it) as you are screwing cheap metal screws into a fairly nice chunk of steel. And not too much torque. Those screws hold that magnet in place, but are not likely to loosen up. That would have facilitated easy removal by you now.

[robdrobd]

Ok, so what steps am I looking at to get this where it needs to be? I thought I could just drill the heads off, pop the case, get the stubs out with pliers, and then replace the cover and gasket. Does that sound right, or is a gremlin going to jump out of their, slap me in the face, sleep with my wife, and screw up my ride?

[mystic_1]

One is so drilled out I can't believe the head is still on.

It may be that your bit is not wide enough, so you're drilling down the center of the shank instead of separating the head.  Use a bit that is well wider than the shank but narrower than the head. 

mystic_1

[MCRider]

Ok, so what steps am I looking at to get this where it needs to be? I thought I could just drill the heads off, pop the case, get the stubs out with pliers, and then replace the cover and gasket. Does that sound right, or is a gremlin going to jump out of their, slap me in the face, sleep with my wife, and screw up my ride?

Mystic is right. But if (when) you get the heads drilled off you've got a ways to go.

I think you're thinking that the 3 screws hold on a cover? A common misconception. They simply hold the field coil (electromagnet) in place. The cover is the big thing held on by 8 or 9 screws. And if those 3 are giving you so much trouble, I hesitate to think what the next 8/9 will be like.

And as i said, I think the tranny cover has to off as well.

If you pop the heads off the 3 screws you can't go any further without taking off the BIG cover, getting the field coil out and then getting the stubs out.

Once you get the big alternator cover off, there is the reduction gear for the starter drive that will fall off. And the wiring for the alternator you will have to deal with. These are not big deals, but you asked and they are there. You can do it.

You should put a small shim under the centerstand to tilt the bike to the right just a few degrees. When you take the alternator cover off, oil will come out and you'll need a drip pan under it. By tilting it you will limit the oil to a minimum, less than 1/3 cup.

Ultimately those three screws do hold on the finned cover you're trying to install, but that's just for looks. A long way to go for a look. But it needs to be done.

[754]

A few things, the screws do hold a cover on.. an AFTERMARKET FINNED cover.

Once the heads are off you should  be able to drill out the threaded parts easily with a left hand drill bit.

 It is  Possible to do this without removing the cover and ruining the gasket. Get 2 screws around 1.5 inches long, and remove heads. As you take 1 screw out, turn in the long headless one to hold location.. When you get second screw out repeat. When you get third screw out, slip your finned cover over the 2 long headless ones. Then install first screw, then remove a long one and repeat..

 Easy eh..?

 If by chance you take the whole dyno cover off, you do not have to take shifter cover off, just the sprocket cover to undo the wires..

[MCRider]

A few things, the screws do hold a cover on.. an AFTERMARKET FINNED cover.

Once the heads are off you should  be able to drill out the threaded parts easily with a left hand drill bit.

 It is  Possible to do this without removing the cover and ruining the gasket. Get 2 screws around 1.5 inches long, and remove heads. As you take 1 screw out, turn in the long headless one to hold location.. When you get second screw out repeat. When you get third screw out, slip your finned cover over the 2 long headless ones. Then install first screw, then remove a long one and repeat..

 Easy eh..?

 If by chance you take the whole dyno cover off, you do not have to take shifter cover off, just the sprocket cover to undo the wires..

Thanks for the followup 754. I knew I didn't have it quite right. Been a while since I've actually done it.

Your method will work, but its tough either way. He has got one screw out and he should thread an overly long dummy in its place right now as you suggest. To hold the electromagnet in place while wailing on the other screws.