Author Topic: Stripped bolt in top end  (Read 791 times)

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destroyer

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Stripped bolt in top end
« on: May 03, 2008, 08:33:36 PM »
So I've stripped my new '77 CB400F down and I'm ready to pull the motor from the frame to being my rebuild.  On of the  top end bolts is stripped and has pieces of aluminum from the case in the threads?  What can I do to fix this?  Do I tap the hole bigger and run a bigger screw into the new threads, or is there some magic thread stuff I can put in it's place?   Thanks.

Offline 78CB750CAFE

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Re: Stripped bolt in top end
« Reply #1 on: May 03, 2008, 10:03:53 PM »
Helicoil. m6x1 if it is one of the valve cover or cam chain inspection cover bolts. Helicoil kits run around $30 for the tap, inserts and insertion tool, and you will also need a drill, a bit,a tap handle and a tap that matches the final thread pitch of the bolt to clean it up. The stuff is expensive because they know they have you, I mean it is cheaper then a new block or whatever, right?

If you were local I would loan you all the stuff I bought to do the 1 bolt I stripped there, of course they only sell the inserts in a 10 pack.....

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Offline 754

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Re: Stripped bolt in top end
« Reply #2 on: May 03, 2008, 10:14:40 PM »
You should not have to run a tap inside a freshly installed helicoil..
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Offline Jay B

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Re: Stripped bolt in top end
« Reply #3 on: May 03, 2008, 10:16:31 PM »
I'm thinking it's your cam cover like '78 said, right? If you want to get down and dirty you could tap it out with a 1/4" tap and have done with it. But that wouldn't be for a resto. ;D
Jay
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Offline 75750SS

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Re: Stripped bolt in top end
« Reply #4 on: May 03, 2008, 10:37:03 PM »
If you don't want to do it yourself, a local bike shop should cost about $40.  That's what I paid.

Offline 78CB750CAFE

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Re: Stripped bolt in top end
« Reply #5 on: May 03, 2008, 10:39:46 PM »
You should not have to run a tap inside a freshly installed helicoil..

if only part of the thread is pooched, I do a short helicoil in the affected area, and chase the original thread below it just to make sure it is clean after drilling and tapping the larger diameter BEFORE inserting the helicoil. The insert itself does not need to be chased or tapped.
"I believe in the bodies, I believe in the blood, I believe in salt around the rim of the glass because it makes us thirsty, and when we drink, then we all fall in love"
-212 Margarita by The Hold Steady
Build thread:http://forums.sohc