Stripped Valve Head

[sxecafe]

Hey Gents,

When I rebuilt the top end of the CB550, I purchased some stainless allen head bolts. Turns out that they weren't machined perfectly. The worst example of this is one that stripped out the valve head. I have oil seeping out from the top of the head, as I can't get it tightened, even though I have since purchased an OEM screw. Any tricks on getting that thread back in there? JB Weld? Anything?

 

[Sonreir]

Drill it out 1mm larger and tap for a new bolt.

 

[sxecafe]

Ya, I thought of that too. For some reason, that seemed like a bad idea but I have no real reason why it would be...

 

[Rich Ard]

Re: Stripped Valve Head

I prefer to helicoil so i end up with matching fasteners

 

[sxecafe]

I'm listening...

 

[Rich Ard]

Re: Stripped Valve Head

If you tap for a larger bolt, you will likely end up with a larger bolt head which stands out, and you have one bolt that doesn't fit in any of the other holes.

If you use a thread insert (helicoil or timesert) you can use the 'normal' sized bolt afterwards.

Drilling and tapping gives more thread for the bolt; helicoil kits are cheaper if you don't have good taps.

 

[sxecafe]

Nevermind... Got it. That's freakin awesome!

http://www.youtube.com/watch?v=RFYa6sjhh_E

 

[AlphaDogChoppers]

Hey Gents,

When I rebuilt the top end of the CB550, I purchased some stainless allen head bolts. Turns out that they weren't machined perfectly. The worst example of this is one that stripped out the valve head. I have oil seeping out from the top of the head, as I can't get it tightened, even though I have since purchased an OEM screw. Any tricks on getting that thread back in there? JB Weld? Anything?

Helicoil or Timesert

So, did you use anti-sieze on those stainless fasteners? If you don't, they can weld themselves to the aluminum, and rip out the threads. Anti-seize on stainless fasteners is MANDATORY.

 

[sxecafe]

Hey Dudes... I was about to get a Helicoil set... I know that the thread size is 1.0 but I forget if the bold it M6 or M10. Anyone know off the top of their head? I can measure it out when I get home but wanted to see if someone knew so I could order it before tonight.

 

[Bert Jan]

Hey Dudes... I was about to get a Helicoil set... I know that the thread size is 1.0 but I forget if the bold it M6 or M10. Anyone know off the top of their head? I can measure it out when I get home but wanted to see if someone knew so I could order it before tonight.

not sure wich one you mean.. m6 is wrench nr 10 (hex 5), m10 is wrench nr 17 (hex 8 ).

 

[SONICJK]

Its a M6 (and you said 1.0) so its
M6 x 1.0 x whatever length you need in mm

 

[sxecafe]

Thanks, SonicJK. I figured it out this morning before I saw your post. I have one on the way.

 

[sxecafe]

Stripped Valve Head

Got this yesterday in the mail. About to get to work on it:

 

[Rich Ard]

Re: Stripped Valve Head

If you need the kit or replacements in the future, NAPA has a kit that costs less than the Helicoil branded stuff and works quite well.

 

[sxecafe]

Stripped Valve Head

Ah. Useful information!

Got it in. So far it's holding like a champ and was super easy. Still have to set the valve but happy with the process.