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Author Topic: undo the x headed bolts  (Read 1596 times)

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Offline _mark

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undo the x headed bolts
« on: March 08, 2016, 12:23:33 AM »
hi guys. I have to remove the lateral carter to do some maintenace.
Unfortunately the x headed bolts seem to be stucked. I try to undo them but the only result i obtain is that the screwdriver is sliding into the seat damagig the head itself. Is there any trick to undo them? thanks.


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Offline mystic_1

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Re: undo the x headed bolts
« Reply #1 on: March 08, 2016, 05:02:40 AM »
Well first off they are NOT phillips head screws, they are something different called JIS (Japanese Industrial Standard) and phillips head screwdrivers fit them but not correctly.  So, JIS screwdrivers would help.

Secondly, they're probably somewhat seized and you may need an impact driver to get them out.



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Offline drumstyx

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Re: undo the x headed bolts
« Reply #2 on: March 08, 2016, 05:06:22 AM »
Quote from: mystic_1 on March 08, 2016, 05:02:40 AM
Well first off they are NOT phillips head screws, they are something different called JIS (Japanese Industrial Standard) and phillips head screwdrivers fit them but not correctly.  So, JIS screwdrivers would help.

Secondly, they're probably somewhat seized and you may need an impact driver to get them out.



mystic_1

Impact driver is the way to go, but are you sure those are JIS? I seem to recall x heads over 5mm were replaced with Phillips in the late 60s

My engine case x head bolts were definitely Phillips (Phillips 3 preferably for the impact driver)
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Offline _mark

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Re: undo the x headed bolts
« Reply #3 on: March 08, 2016, 05:38:17 AM »
thanks i will buy it. When I will put the bolts on again, will I have to use again the impact screwdriver? thanks
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Offline madmtnmotors

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Re: undo the x headed bolts
« Reply #4 on: March 08, 2016, 05:52:35 AM »
Quote from: _mark on March 08, 2016, 05:38:17 AM
thanks i will buy it. When I will put the bolts on again, will I have to use again the impact screwdriver? thanks

NO!NO!NO!

Just use the JIS screwdriver to reinstall. Be sure to get JIS bits for the impact driver too. drumstyx may have gotten lucky, but these case screws are indeed JIS.
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Offline mystic_1

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Re: undo the x headed bolts
« Reply #5 on: March 08, 2016, 05:54:34 AM »
Yeah standard tightening torque on a 6mm fastener is something like 5 foot pounds, no impact driver needed.

If being 100% stock is not important to you, you may consider replacing them for allen screws, you can get kits for the whole motor on Ebay.  That'll make reinstallation easier as well as any future removals.

mystic_1
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: undo the x headed bolts
« Reply #6 on: March 08, 2016, 10:02:08 AM »
+1000 on the allen heads
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