Argh!!..Stripped 6mm Valve Cover Stud..How Much To Open Out?

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Guys,

I've got a stripped 6mm Stud..I detect Chemical Metal at work from a previous owner Sad

Is it best to Try again with this method or open it out with a tap and chaser..if so...how much do I go out to?

Cant take engine down again. I'll have to shoot my self Smile

mo650chopper

Are you refering to one of the three studs that hold the valve covers on? I have one stripped on mine so I'm interesteed in a solution as well, maybe a helicoil fix?

jayel

yes heli-coil it, the kit costs about $25 but its a permanet fix and you'll have extra coils for the next one that goes

mo650chopper

jayel wrote:

yes heli-coil it, the kit costs about $25 but its a permanet fix and you'll have extra coils for the next one that goes

You don't happen to have a link to a online available kit?

jayel

type "heli-coil kit" into search google or whatever browser you use, lots of hits

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Wow, I didnt know you could DIY Helicoil...I'll 'ave a look Smile

xs1961

Once youve got one of these kits you'll be buggering-up threads just so you can play at helicoiling... Twisted Evil

Great peice of kit Jake..

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

They dont seem to cost 25 bucks though LOL...Bloody Americans, always taunting me with their prices Smile

LOL

How have I survived without one? aye?

I am gonna have a word with my local engineer. He's been taking money of me for yonks for helicoils..

I was gonna open it up two sizes, that would have been a shame wouldnt it? Smile

jayel

well that would have given the next owner (in due time) a talking point (what was he thinking boogering it up like that) now he'll comment what a fine fellow and ace mechanical genius you obviously are/were

your engineer? mechanic over here, yes he saw you coming but now your wise to his wily ways

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Not really, and engineer is the guy, or at least thats what I would call him, you would see for fine engineering work, like rebores...etc..

tacoswild

I think we'd call that a machinist here, but not sure. People with the title engineer design things like bridges, highways, electronic circuits... a wide range of things you design and other people construct.

I had the same problem as you last summer and took the recommendation from the guys here to use a helicoil. It worked great and was actually very easy to install. The metal must be pretty soft around those valve covers considering how stripped out it was and how easy it was to tap the grooves for the helicoil. I'll probably do a couple more this summer because it wasn't the only one losing it's grip.

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Guys,

One of the things that worries me, is that I only have a cordless in my low power garage (only 150W 240v).

The guy who sells the kit local to me, tell me it needs a 6.2mm drill to open out and then tapping with the included tap.

But the drill out needs to be pretty perfect otherwise the coils will get ruined as you insert them..

Personally I build model aircraft, been messing with bikes for years (2 strokes mostly), I thought I might have a steady enough hand...but he thought that a vertical drill would be the only way...

Is he being over cautious ? I think so ....?

bulldog1980 · 650Rider Supporter Joined: Mar 28, 2007 Posts: 175

Lets put it this way.. what is your options if you mess up? Have you ever done this procedure before? That maybe why the Salesperson was telling you what he did... Also by telling you to use recommended specs it protects them (salesperson/company) if you come back and say hey this bloody thing didn't work with the tools I had.. then the Salesperson can say well I told you to use recommended tools. My personal opinion is to go with what they suggest.. worse case scenario you have just bought yourself a new tool....

jayel

you'll do fine with a hand held the bit will follow the old hole as long as you try to keep it straight to get the into a vertical posistion you'ld have to suspend the whole bike or remove the head, it ain't rocket science, even if the hole isn't perfect so what? you're going to run a tap in there anyway that the important part --- FYI 6.2mm = .24428 in. closest metric drill is 6.248, closest in. drill is .246, or a ''C'' in letter drills

tacoswild

I had a titanium coated bit of the size recommended on the back of the package so I used that with a hand held drill and it followed the hole straight in. It looked like all it did it clean off what's left of the old thread, which in my case was next to nothing. I was careful and I don't want to encourage you not to be, but at least on my old 71 it was surprisingly easy to do.

jimdi · 650Rider Supporter Joined: Oct 27, 2005 Posts: 512

Autozone here sells the kit - complete with drill bit - epoxy - helicoil and helicoil tool - I think for less than $20. It's been about a year since I bought one - worked great.

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Thanks guys for the "extended" advice Smile

You're right, I think the guy is being over cautious, but I also think its best I use a hand drill, thing go wrong to quickly with my cordless, and I think its got a slightly bend shaft as well...

XSAndy

What ever you do try not to play around with the bit sizes. Use the one in the kit not the nearest you have. And don't believe that the drill will follow the old hole. Take it easy and you'll get there. Can be done with motor still in bike happily. Razz

jimmythetrucker · Full Member Joined: Mar 12, 2008 Posts: 1283

One piece of advice: Lay your new drill bit on the bench. Clean up the stud and lay it on the bench alongside your drill bit so that the end of the stud that threads into the head lies next to the business end of the drill bit. Now get a small, narrow strip of duct tape and wrap it around the drill bit at the upper end of the threads on the stud. The idea is to use that band of tape as a depth gage on your drill bit so you don't drill any deeper than you absolutely have to.

XSAndy

Great thinking "99"

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