81 GS1100EX Crankcase stud question.

[retrex]

Hi all, I just need to get some feedback before I do something I may be sorry for.

I have a 81 GS1100EX I am working on. Bought it used with 20k on the speedo. Indications are previous owners weren't good with a wrench. Compression 135, 135, 70, 120. I thought that I would retork the head bolts and readjust the valve lash to see if I can bring up the compression on the bad cylinder before venturing into replacing the head gasket and/or doing a valve job. I don't mind doing it, I just don't want to do something unless it needs to be done.

Anyway, while losening the headbolts for retorking the #7 (outside of engine) bolt I accidentally losened the stud from the engine block. I did spray the bolt down with liquid wrench before attempting this. No snide comments please. The bolt was just too rusty. In hindsight maybe I should have use the impact air gun. But this is where I am now. I haven't completely unscrewed and removed it from the engine yet because I don't know if there are any bad consequences to this action.

I have checked both my shop and Clymer manuals but they don't give me an indication one way or the other. My instinct is telling me to unscrew the stud, take it out, put it in a clamp and remove and clean the threads with a die and run a tap through the nut. Then reinstall and have done with it. Am I right or am I venuring into the dark side. Feedback is appreciated.

[Hap Call]

Re: 81 GS1100EX Crankcase stud question.

I have checked both my shop and Clymer manuals but they don't give me an indication one way or the other. My instinct is telling me to unscrew the stud, take it out, put it in a clamp and remove and clean the threads with a die and run a tap through the nut. Then reinstall and have done with it. Am I right or am I venuring into the dark side. Feedback is appreciated.

That is what I would do except I would put a little medium strength Loc-Tite on the threads going into the case.

Hap

[jimcor]

I agree with Hap, but I would add some snide comments just on general principles.

[retrex]

[That is what I would do except I would put a little medium strength Loc-Tite on the threads going into the case. ]


You are reading my mind Hap. I would think that is the right thing to do. I just had a couple of concerns. The first is that is there anything that is being held in place by that stud that will dislodge and/or fall off into the bowels of the engine if I remove the stud from the block? I doubt it, but I thought that I should ask. The second is that I wasn't certain that the case thread gallery for the stud remains dry when the stud is removed. I haven't been this deep in my engines yet.

jimcor, let he who has not done a bonehead thing cast the first stone.

If anyone else has anything to add, or warn me of please do so. If not I will do the deed this weekend.

[IanFrancisco]

Most head studs don't do anything but go thru the head and cylinder. But to ease your mind, check bikebandit.com to see the parts fiche for your bike. There may be a locating dowel (tube actually) that the stud goes thru but if the head is left undisturbed there's nowhere for it to go.

[Hap Call]

I just had a couple of concerns. The first is that is there anything that is being held in place by that stud that will dislodge and/or fall off into the bowels of the engine if I remove the stud from the block?

There is nothing that will fall off into the case.

I doubt it, but I thought that I should ask. The second is that I wasn't certain that the case thread gallery for the stud remains dry when the stud is removed. I haven't been this deep in my engines yet.

This is a good point. If any oil is in the threaded part of the block where the stud screws in, you could crack the aluminum block with hydraulic pressure as you screw the stud in. If this stud is one of the four outer corner studs this is a real possibility because they use the same bore that the studs run through as oil passages to the cams. If it is not one of the four corner studs, you should be okay. To be on the safe side you could take a gun cleaning rod, put a small cloth patch on the end, run it down the stud hole (he, he - he said stud hole!) and wipe out any oil that may be down there.

Hap

[jimcor]

take a gun cleaning rod, put a small cloth patch on the end, run it down the stud hole (he, he - he said stud hole!) and wipe out any oil that may be down there.

Hap

I believe this statement contains a snide comment.

[retrex]

[Most head studs don't do anything but go thru the head and cylinder. But to ease your mind, check bikebandit.com to see the parts fiche for your bike. There may be a locating dowel (tube actually) that the stud goes thru but if the head is left undisturbed there's nowhere for it to go.]

Ian, I looked at the BB schematic and all the others that I could find and they weren't definative in what they showed.

[This is a good point. If any oil is in the threaded part of the block where the stud screws in, you could crack the aluminum block with hydraulic pressure as you screw the stud in.]

Hap, I am very wise in that I know that know that I don't know a lot. This is why I stopped before I fully unscrewed it and took it out (don't go there jimcor it is just to easy).

The stud in question is one of the four that reside on the outside, not under the cam cover, of the cylinder head. One on each side of spark plugs 1 and 4. I think it is #6 or #9 head bolt. I can never remember the bolt sequence numbers so don't quote me on the #. If what your your saying is correct then I am good to go with the extraction.

There was one other problem which I didn't bring up because if it happened here then I am already screwed. I heard that under certain circumstances there is a chemical reaction between steel, Loctite, and aluminum. They all blend in harmony and become one. If that is the case here then I may be pulling a nice aluminum plug out of my crankcase. I hope that this is not the case.

[Hap Call]

There was one other problem which I didn't bring up because if it happened here then I am already screwed. I heard that under certain circumstances there is a chemical reaction between steel, Loctite, and aluminum. They all blend in harmony and become one. If that is the case here then I may be pulling a nice aluminum plug out of my crankcase. I hope that this is not the case.

I've used Loc-Tite Blue for years on my 1100EX and never had a problem...I'm willing to bet you will have no problem either. It can be an issue when salt water is involved but that is something you don't have to worry about. The only other issue I've heard of with Loctite is that it needs an "active" metal to work. Pure aluminum is an inactive metal but our cases are actually an aluminum alloy and handle Loctite well.

Hap

[retrex]

Follow up on 81 GS1100EX stud problems

[I've used Loc-Tite Blue for years on my 1100EX and never had a problem...I'm willing to bet you will have no problem either. It can be an issue when salt water is involved but that is something you don't have to worry about. The only other issue I've heard of with Loctite is that it needs an "active" metal to work. Pure aluminum is an inactive metal but our cases are actually an aluminum alloy and handle Loctite well.
]

Good, one less thing to worry about. Thanks again for the input.

[retrex]

Post subject: Follow up on 81 GS1100EX stud problems

Thanks again for the help. Stud is locked down and compression is up. 150, 140, 135, 135. I love it when a plan comes together.