Snapped CCT bolt

[Indiesol]

Hello all,

I'm a GS fan out of Vancouver, WA. I'm currently working on my 2nd GS, a 1983 GS850G(D?).

The bike was dirty upon purchase, having sat for a few years, but looked to be in really good shape. I removed the carbs without issue and rebuilt them, and then when attempting to install them back on the bike, I simply couldn't get them seated all the way into the intake boots. Upon looking at the bottom of the carbs, it appeared they were making contact with the cam chain tensioner. It was at that time that I noticed the bottom bolt that attaches the cam chain tensioner was missing. Not only that, but I could actually see daylight between the tensioner and the cylinder. After removing the tensioner (following the manual's instructions), I found that a previous owner had snapped the bottom mounting bolt off. What's left of the bolt is still in the cylinder, almost flush with the gasket surface.

I'm fairly certain the best course of action would be to attempt to drill out what's left of the bolt and use an EZ out, but I wanted to run it past you lot first. Has anyone done this before ? IIRC, there shouldn't be anything to worry about falling into the case, I believe it's just a bolt. Hoping someone can confirm. I can take pictures if needed, but I don't have any handy just yet.

Thanks in advance for the help.

[tkent02]

Try welding a nut on what's left of the bolt, then unscrewing it while it's still fairly hot.
It's nearly impossible to drill straight, as the steel bolt is much harder than the aluminum around it...

There are other possible techniques.

[Big T]

Todd

That's going to be a bitch

Start hitting it with penetrating oil 3x daily

It is a bolt

If it's sticking out, weld a nut to it

Don't use an EZ out, because you can't get the broken EZ out from a 6mm hole

Pull the carbs and whatever, get some room back there, drill very carefully with the smallest possible bit, then go progressively larger. Using reverse twist bits ( from HF) should cause it to come out

Use the unbroken bolt to determine the drill depth, don't drill in too far

Good luck and I hope you don't have to pull the motor/cylinder

I've got some spare 850 parts that may fit (like an entire motor)

[Indiesol]

Unfortunately there isn't much material there to weld to. It's very close to flush with the gasket surface. I hear ya on trying to drill it straight. Just don't know of any other options.

Would love to hear about these other techniques, but I'll post a picture before we go too far in...I get off work in a couple hours and will get a visual up here...

Edit:

Hey, Todd! Long time no see! I started with the heat and PB Blaster last night as soon as I saw it. It was making the carbs a bitch to reinstall, so they're still off. I believe it's the same length as the upper LEFT bolt, correct?

I'll pick up some reverse bits from HF on my way home.

And here I thought I was going to be able to fire it up yesterday!

Thanks for the advice. I may just hit you up for that motor.

[Agemax]

as said, hit it with penetrating oil for a while, then get some heat on it and get a small pin punch or centre punch and see if you cant tap it round anti clockwise to unscrew it.

those bolts shouldn't need thread lock so its probably just rust holding it in

[hjfisk]

They probably broke it putting it in , so if you can take a dremal and carefully cut a small slot in it enough to get a small screwdriver on it , it will probably back right out

[loud et]

as said, hit it with penetrating oil for a while, then get some heat on it and get a small pin punch or centre punch and see if you cant tap it round anti clockwise to unscrew it.

those bolts shouldn't need thread lock so its probably just rust holding it in

+1, this is a naturally oily area if there were any leaks and its likely with a punch it will spin out somewhat easily.
It will be loosely goosey or frozen in time. Lol
Hope its the former!
A lil heat and a lil lube and you may get lucky.

[Indiesol]

I got it out.

First of all, thanks everyone for the replies. I have to admit I was hesitant to dremel or drill so close to the gasket surface, but at some point you have to stop worrying about all the things that could go wrong and start looking forward to all the things that will go right.

Here's the culprit....



Upon getting home from work, I immediately took a picture as promised. After taking the picture and giving what was left of the bolt a good look, I thought I might be able to cut a slot a few MMs deep in the bolt as suggested. I'm not a good enough welder to feel comfortable welding a nut on there myself, so that was definitely a last resort. After a few minutes with my trusty dremel, I had what looked to be a decent spot for a flathead to go.

I figured some more heat could only help things along and this is where I believe the luck came into play. As I was heating it, I noticed a small drop of oil seep out of the threads. Being that I had wiped off the gasket surface after cutting the slot in the bolt, I got a little giddy. I sprayed some PB Blaster in there just in case. I figured, I'll just put a tiny bit of pressure on it. If it doesn't turn, I'll let it sit a few hours and heat/PB blast it again.



Well, I'll be damned if it didn't turn quite easily. I guess it was the former, Loud ET.

Again, I appreciate the help of the group. You guys rock.

Here's a picture of the bike how it sits. Can't wait to get her going. I miss my old 1100G something fierce.



PS: Don't be jealous if your garage doesn't have a curiously large doll house in it. They're not for everyone.

[barnbiketom]

CONGRATS!!

time , patience and help usually wins!!

I've seen a lot of bolts snapped cause the PO just didn't know how tight was too tight.. and most were not bottomed out like yours, and came out pretty easy..

[snackie]

How did you heat?

Hi, I'm in a similar situation and snapped two valve cover bolts when I was removing them. How did you heat the cam tensioner area to remove the bolt?

Thanks!