I've got the kind of impact driver you described, and it works pretty well. The impact guns you see in auto shops probably work better, but are a lot more expensive. Get either, and use it frequently. These screws and bolts are stuck more often than not and you're better off using the driver than risking stripping the head and having to drill it out. There are other things you can do to loosen the screws up, PB Blaster, heat, etc, but most of the time the impact driver gets the job done by itself.

 

Use an open end wrench only if there is no way to use a box end or a socket.
If it doesn't start to loosen right away try tightening it first then remove if possible.
If that doesn't work then use an impact driver.
Unfortunately some may break.
If they break and you end up with a portion protrucing out of the case, use a good quality pair of vise grips first, NO cheap ones. If it doesn't grip then you can try a small pipe wrench or stud remover. The quality of the tool will determine your success.
If you have to drill them out then you'll want to use "Time-Serts" for the repair, not heli-coils. Use "left hand" drill bits using the drill in reverse. Sometimes the heat and vibration will break the bolt loose and unscrew it while drilling.

 

I've got the kind of impact driver you described, and it works pretty well. The impact guns you see in auto shops probably work better, but are a lot more expensive. Get either, and use it frequently. These screws and bolts are stuck more often than not and you're better off using the driver than risking stripping the head and having to drill it out. There are other things you can do to loosen the screws up, PB Blaster, heat, etc, but most of the time the impact driver gets the job done by itself.

On 8mm and higher an impact gun will work, the 6mm bolts will most likely snap off with the gun

 

Sounds like the manual impact driver is my best bet. I'll also try the vice grips since I used that method on small throttle body screws on my car.

 

Sounds like the manual impact driver is my best bet. I'll also try the vice grips since I used that method on small throttle body screws on my car.

Only use good quality visegrips and not on the head of the bolt. They are reserved for when all else has failed and the bolt has broken off.

 

So I have an update...

I tried an impact driver and it stripped the screw pretty well in one go. I was going to try a reverse bit or screw remover but I've heard that they aren't that great.

At this point I think welding a nut on is going to be my only chance. Does anyone know what kind of metal the screw is and what the engine is? I have a friend who is a pretty good welder so I'm keeping my hopes up.

My last resort would be to drill it out in which case I'm thinking that a self tapping screw would be okay to use in replacement since it just needs to hold the tach cable from falling out.

I also tried a brake line wrench on the head bolt in case it might break free with the added control but it still slipped. I don't want to try anything but a 6 point socket on it at this point so I need to get the tach cable out.

Here's a picture of the wrench I tried on the bolt and one of the stripped screw.

The head of the bolt that I cant get to can just be seen behind the engine cover right below the tach cable.

I probably won't get to ride before winter but a glimmer of hope would be nice. Otherwise I'll just ride with a bottle of oil with me to keep up with the oil leak :?

 

I would use a reverse drill bit, left hand, Carbide, new, 6mm.
Drill it out until the head of the screw comes off and pull the cover. Is that bolt holding the cover? Doesn't look like enough room for a welder to get in there until the tach drive is removed

 

The screw that is stripped in the picture doesn't hold the cover on. It holds the tach cable in place. The tach cable comes out right over the cover bolt so I can't get anything but an open ended wrench on it (bad idea). If I can remove the stripped screw then the tach cable can be removed and then the bolt will be easy to get to with a 6-point. I wanted to weld the nut onto the screw that is facing the camera in the picture...the one that is stripped to ****.

 

Boogers :x I was afraid you'd say that.
Have you tried tightening both the screw and bolt? Sometimes it'll break them free.
Have you tried driving the just the screwdriver tip of the impact driver into the screw to get a better bite? Or tried the next larger tip?

 

Yep. I've tried the tightening trick on both with no success. The screw is so stripped I don't think any phillips head is going to do anything to it besides chew it up more. I guess I'll try the welding trick. The way I've seen it done is put a little ball of metal on the head, put a nut over the ball, put metal inside the nut to connect it to the first ball of metal, unscrew.

If I have to drill it out can I use a self tapping screw to replace it since its not really securing the cable but rather just keeping it from popping out of the motor?

 

I don't know. I'd use a helicoil myself. Hopefully someone comes along with some other ideas for you.

 

Here's the method with the welder I was talking about. If that doesn't work I'll just deal with the leak. Is it safe to use sealing additives in the oil?

 

Very interesting and informative video. Definitely worth a shot and probably will work
No you cannot use any form of sealing additive with an air cooled motorcycle engine. I wouldn't use one on any engine.
Worse case scenario here is get another cover and cut this one up

 

I've allways cut a slot in them using a dremel with a cut off wheel at a good angle to use a drift punch and a hammer on one side of the slot, they've all come loose for me.

 

Here's a very long post I wrote about removing stuck bolts/screws a while back:
viewtopic.php?f=44&t=12524&p=98174#p98173


For the screw in your picture, here are some ideas:

1) soak the screw in penetrating oil (PB'laster, acetone/ATF mix) - put fresh oil on each day for a week

2) use a punch to "mold" head of the screw back to the proper shape -- you can kind of "push" the disturbed metal back into a cross for a phillips head screwdriver, and try an impact driver again. It won't be as good as new, but might give you one or two more tries. Make sure the driver is set to turn the right direction (loosening rather than tightening). Try standing on the opposite side of the bike and brace it with your legs (will require you hammer the driver while leaned over the bike). Make sure the bit is firmly seated in the screw, and you're applying slight counter-clockwise pressure. Give it a good, sharp blow. (Good technique really helps when using a manual impact driver.)

4) given the location, I would not use a torch on it, but you could try using some of that liquid freeze stuff (http://www.loctitefreezeandrelease.com). Fair warning - I've never tried it myself. Or if you know someone who has access to liquid nitrogen, that's the ticket.

5) try turning it by cutting a slot, setting punch on the outer edge and hammering, like captb suggested

If it's stuck enough that it won't come out after all that, I would skip trying an EZ-Out. Go straight to drilling it out, or welding on a nut. If welding, make sure you grind/clean the head of the screw before you weld, or all that schmutz and penetrating oil will infect your weld and the nut will shear off. (Ask me how I know.) Helps also to weld a washer onto the head of the screw, and then weld the nut to the washer. Use more heat then you would normally (turn up the volts on the MIG).

I hate stuck bolts with a passion and wish you good luck in your battle. Long live anti-seize compound.

 

+1 on what Isosceles said above in his steps #1 and #2. That machine screw head doesn't look that chewed to me. The whole idea of the hammer-type impact wrench is that the hammer blow seats your cross tip screwdriver as it shocks the thread and simultaneously attempts to unscrew the fastener. I've gotten some out that were in worse shape than in your picture. Of course, yours could be more stubborn. I'm just saying I wouldn't go to more drastic steps until it is well and truly chewed and there is no more hope for using your impact screwdriver. Hopefully, it will break loose before it really gets nasty.

 

Just a quick update with some follow up questions.

A friend of mine came by with a different impact driver and it worked. I got the head cover off and everything looks pretty clean. At this point I don't really see the need to go any further since it ran fine except for the oil leak. Heres some pics

I did notice some pitting type stuff on some of the rocker surfaces. It doesn't look like oil starvation because the rest of the metal is smooth. Is this common? Heres a closer pic of the worst one

 

Just a quick update with some follow up questions.

A friend of mine came by with a different impact driver and it worked. Good deal

I did notice some pitting type stuff on some of the rocker surfaces. It doesn't look like oil starvation because the rest of the metal is smooth. Is this common? Heres a closer pic of the worst oneThis is VERY BAD. The rocker pad has lost it's hardening and will shortly be eating the cam for lunch. You can either replace the rockers or have then resurfaced and hardened. Need to check the cam carefully for any damage that may have already been done

 

I haven't seen anything that bad before without oil issues. Then there is usually plenty of other indications to suggest heat and wear. Could it be a casting fault?

 

Well it looks like those rockers are about 50 bucks new. I think I'll look around for a machine shop to take care of them.