Topic: Stuck screws in mag cover

[zxshep]

I have been trying to get the mag cover off to take a look inside and get it cleaned up and the factory philips head screws must be welded in there - every last one of em.  It doesn't help that someone else has had them out before and wallowed them out a little, which makes getting a good grip that much tougher and all the more important.

Anyone have some tips or tricks on coaxing these fiendish devils out without buggering things up?

Thanks for your time and help.

[Rookster]

The screws are a type of philips called JIS or Japanese Industrial Standard.  The standard phillips will just wallow out the heads.  The way to remove these is with an impact driver.  The kind you strike with a hammer.  You would really want a JIS bit for the impact driver but a phillips bit will also work.  Once you get them out replace them with Allen head bolts.  If you come across one that won't come out or the head is so damaged you can't get a bite on it then just drill the head off.  Once you get the cover off you can unscrew the rest of the screw with a pair of vise grips.

Scott

[beemerbum]

This high quality JIS screwdriver is also an impact driver. Pretty much essential for work on old Japanese motorcycles. The one shown is a #2 tip. 1's and 3's are also available. This one is about $15 at amazon. Worth every cent

[BenelliSEI]

Vessel also sells a set of JIS tips for a standard impact driver. Best investment you will ever make!

[zxshep]

Thanks everyone. Off to Amazon I go...

Is there a good source for replacement Phillips or Allen screw sets?  I’ll need screw sets for the mag cover, clutch cover, and starter/countershaft cover.

Thanks again for your time and help.

[beemerbum]

Used to get the "Phillips" JIS screws from Tamaiya. at  a reasonable price for the entire engine set. Could be more difficult now with their covid shipping situation. I've seen both JIS and Allen sets all over eBay. IMHO, Allen heads look out of place on these bikes, unless you want a more custom appearance. Allen screws are more easily overtorqued.

[maxheadflow]

Stick the right sized phillips into the screw. Turn from side to side.  If you can feel play grind a little off the tip.  Once set take a hammer and tap the end of the screwdriver and try to remove. If it don't loosen, try again with the hammer. This works better if you have the right sized 3/8 socket phillips.

I have a set of Kowa  T handles and they definitely look more like pilllips then the jizz spec. 

[Alan F.]

I'm with Rookster, just drill the heads off.

But after you've got the cover off at least some of the headless screws will turn out by hand. It's the heads that were frozen to the cover, not buggered threads.

[markmyodb]

Looks like this topic is well covered here.

http://forums.sohc4.net/index.php/topic,64268.0.html

My two cents is a good impact driver like a Dewalt XR works well for both breaking free with a properly selected tip, and works well with a extractor bit as it drill till it bites, then hammers it loose.

[jgger]

On the bad screws use a flat punch and hammer to peen the buggered up metal back into the head. This will give your driver better grip for that last hail Mary whack. This method has served me well in the past.

[Alan F.]

For me, if I know i won't be reusing the screws.... Drill the heads off.