Topic: All advice appreciated don't want to mess up

[spitfire]

I really do not want to mess this one up, I have one broken exhaust stud on my CB750F1, there is about 1 inch remaining, the engine is nearly out so I will have it on the bench when I try to remove the stud.
The materplan is to carefully clean the area at the base of the stud, leave it soaking in WD40 for a couple of days, giving it a good tapping with a blunt object to try and jar the threads, give it some heat (only got my plumbing propane torch though), and then apply the roller type stud extractor.
Does this sound like a realistic plan ?
I do not really want to go down the drilling path.
All and any suggestions appreciated.

Cheers

Dennis

[byurko]

I've use PB Blaster with great success in the past.  Much better than WD40 IMHO.

http://www.pbblaster.com/store/moreinfo.cfm?Product_ID=1

Good luck!
Bryan

[volthause]

I second the PB Blaster nomination. For me it has been much better for extraction than the WD.

[ProTeal55]

I am a big fan of WD40, but for this job, I would say PB Blaster is the best bet.

[TwoTired]

If you have an inch left, you can use this tool if there is clearance around the stud:
http://www.sjdiscounttools.com/skt92502.html

An open flame torch will take the paint off the engine.
Find an electronic supply place that sells cold or freeze spray.  To save the paint you can try alternately cooling the stud mount area and/or the stud.  Dry ice is also usefull.  You can also torch just the stud.  The idea is to get the two metals in a different thermal expansion/contraction mode, thus fracturing the thread interface fit. Sometimes, a sharp rap at the end of the stud like you were tapping it into the head will help shock it loose, too.
Then put on your stud remover and twist.
Alternately, you could thread the remaining stud post and put two jam nuts on there.
 Rarely, no matter what you do with incremental force, the danged thing breaks off anyway.

Is there a wire EDM capable machine shop in your vicinity?  This can remove the stud remainder with effecting the cylinder head.  And, it might be cheaper than buying the tools to do it yourself.

Good Luck!

[dusterdude]

pb,pb,pb

[mcpuffett]

take your time spitfire use some penetrating oil and let it soak, i have succesfully removed bleed nipples and exhaust studs this way, but you have to be patient    mick.

[SuperVel]

I like to give it a good bath of penetrating oil and then try it.  I like to go a little bit each way CW and then CCW, repeating over and over, increasing the pressure slowly until something loosens up.  Sort of like tapping the thread in the first place.  Best of luck.

Marty

[Jerry Rxman Griffin aka MuthaF'er]

Have you thought about using vise grips?

[KB02]

Allow me to scare you with my story:

Same situation. Exhaust stud. One inch left.

WD40, Liquid wrench, and Break-Away all failed me.

The propaine torch just didn't have enough heat.

The welding torch also didn't have enough heat.

Two nuts, locking each other on, only proved to recude the size of the stud as it broke off in ever shorter increments.

Vise grips... Ha, ha, ha, ha......... no.

Taking a saw and cutting slot in the end to try an use an impact driver didn't work.

the stud remover that Twotired listed (which I should have tried much earlier in the process) also did not work.

Drilling and re-tapping... now that worked.

You may have better luck with any or all of the above, and I never thought of the EDM process. Just becareful with your engine and acknowledge when it is the proper time to give up and drill. You do have one advantage over me. Your engine is coming out of the frame, mine was in when it happened.

Good luck.

[spitfire]

Wow, thanks guys, I have a feeling of inevitability on this one but will try all the ideas, except cannot find PB Blaster in the UK.
The stud actually broke level with the bottom of the nut and I was only using a standard sized spanner (wrench ?) so no huge leverage on it at all, which does not instill me with confidence, I can see it breaking of at the threaded section, and I'll end up drilling.
Will spend the next week giving the hot and cold treatment (Loctite freezer) soak it in WD and keep tapping it with a small (ish) hammer before I tried the extractor (roller type), Strangely enough I tried the extractor on my F2 engine (on the bench) and it fitted easier than on the F1 ?
Just for general information I just recieved a copy of a Honda CB750F2 /K7 manual from David Silver Spares, it's dedicated to these two models and looks very useful.

Thanks for the advice

Cheers

Dennis

[oldbiker]

One piece of advice. If you get to the point where you decide you must drill and tap, DON'T cut the stud off flush with the head. Leave a short bit standing. Take a short piece of Silver Steel (I think you call it tool steel in the States) drill through with a small drill and then drill half way through with a driil which gives a snug fit on the remaining stud. If you now put this onto the stud and run the small drill through, it will ensure that you drill centrally into the remains of the stud. Without this guide  the drill will wander and damage the threads in the cylinder head but with the pilot hole any subsequent drill will follow the center line. If I have not made myself clear, come back and I will do a drawing.

[spitfire]

Sounds like a great idea for a guide, if I do get into that position I will give it a try.
Now that the engine is out of the frame I also have the option to lug it to a machine shop if the stud breaks.
Two Tired raises another question for me, he mentioned about ruining the paint on the head, however the paint is already shot, I have asked on another forum about engine enamal but got no definative answer. The best suggestion was to use radiator paint, does anyone know of any other alternative ?

Cheers

Dennis

[oldbiker]

Hi Spitfire, we in the UK can buy spray cans of HTP (high temperature paint) I am not certain what colours are available but it's a possibility.

[cb(r)]

is it to late to get on the PB band wagon?

[dusterdude]

its never too late for the pb bandwagon.

[cb(r)]

O.k.  thanks duster. then  It is official i am on the wagon!
  here is my suggestion to fix your problem make sure you do this in order.  spray pb, wait while drinking  a beer. alittle more pb a little more beer.  repeat til your nerves are calm then clamp vise grips on and a couple of tugs of the handle.  the vise grip handle i mean.  should work.

[cb650]

No band wagon I want to get on the bike/girl in cbrs avatar
OH yea if you have to drill use lefthanded if your drill is reversable.   



                   Terry

[spitfire]

I'd get on the PB bandwagon but they don't sell it in the UK !
Have been spraying WD40 and Locktite Freezer on the stud and tapping it with a hammer everytime I walk past it. Will start the Heat treatment soon, but as I have decided to do a complete restoration on the bike I have lots of time now

Thanks

Dennis

[spitfire]

Well that did not work out very well (see photo), but it has made my mind up on something that has been nagging me. I was going for a quick refurbish and get back on the road as quickly as possible, but the state of the frame (rust) convinced me to strip the whole bike and get it re finished. Then I thought about getting it all finished and needing engine work so the motor would have to come out again and scratch all that shiny new paintwork. So the broken stud has made my mind to do do a top end overhaul.

Thanks for all the advice anyway.

Cheers

Dennis

[scunny]

welcome to rusted/frozen/seized/rounded/stripped bolt city. All rooms are taken at the moment so could you please take your broken stud and find a seat.