Topic: CB750 Cylinder Studs

[umlaufa1]

I am rebuilding the top end on my 1978 CB750K and I have decided that I should probably replace the cylinder studs. Unfortunately, Clymer and other resources do not have a good 1,2,3 step approach for doing this, so after searching through the forums and Google here is my game plan...

1. USE APE HD Studs (CS750H).
2. Use a cylinder stud puller, PB blaster, and possibly some heat to remove the studs.
3. Clean up the holes.
4. Apply thread-lock to the new studs and install using thread installation tool.

Can anybody confirm/critique these steps? On step 3 specifically, what can I reasonably expect as to the condition of the threads on the cranks case...will I need to use a thread chaser? On step 4, how will I know when the new studs are seated properly ensuring that all of the studs are at the proper height.

Any help is much appreciated...lots of knowledgeable people out there!

[Don R]

I double nutted the original studs to back them out. A thread chaser would be handy. It seemed to me tapping on the end of the stud with a hammer helped loosen it up and the vibration may have allowed the PB to soak in a little more.
 I also have questions about stud installation, Some have suggested torquing them in lightly, I was always taught to not bottom a stud in it's hole tightly. The reason was it will bind the threads and not allow for expansion. I'm not sure how correct that info is for our application.

[SOHC_guy]

On cylinder studs, I like to wipe the threads with Bel-Ray ass'y. lube, or any other molybdenum based product.
Bottom them lightly into the upper case. I do this to eliminate false readings when torquing the head.
Wipe the upper threads with oil, coat the nuts + washers with oil also.  Torque the head to specs, then come back in 12 to 24 hours and torque them again. Never a problem.

Cheers

[VTCBike750]

Now I haven't done this, but read a fair amount in preparation to do so. Not sure threadlock is advocated.
What is a thread installation tool?

Interested in this part, "Bottom them lightly into the upper case. I do this to eliminate false readings when torquing the head."

[umlaufa1]

The thread installation tool:  racetoolz.com

You can also use the double-nut method. Here are some instructions I found researching this topic. I believe these are APE's installation instructions.

1. Long threaded end must be installed in the crankcase.
 2. Note stock stud length location before removing, There are two different stud lengths.
 3. After removal of stock studs, thoroughly clean holes with solvent and blow out.
 4. Using two wrenches, lock up two 8mm x 1.25 nuts on the short thread end of stud. Dip long end in oil and install in noted location, bottoming out, then use a torque wrench torque to 8 foot pounds maximum.
 5. Install head and following manufacturer's torque pattern, torque head nuts to 20-22 foot pounds.

[HondaMan]

Umm...don't over-complicate it?

Double-nut the old ones, and simultaneously grab the shaft tightly about 1" above the case to break it loose with a wrench and Vise-Grips.

On installation, torque them in to 8 ft-lbs by double-nutting the new ones. Be sure to grease the new ones or apply anti-seize, to the threads.

If one breaks off, have a welder attach his ground clip TO THE STUD, then weld a 1/4" nut on the end of the stub. The welding heat will remove the sticky corrosion and widen the threads a hair, and it will back right out after cooling.

[koendd]

let's drag on old cow out...

I'm about to install hd studs in my F2 bottom end.
Cleaned the holes and went through them with a thread chaser. But the 2 middle holes in the front (exhaust side) lead into the crankcase..
How are you supposed to bottom them out if it's open? or does the hole get smaller in the bottom?

[flybox1]

they should bottom out no prob.
I used a tiny ammt of red locktite, and let them set up overnight.
torque to 8ftlbs

[madmtnmotors]

let's drag on old cow out...

I'm about to install hd studs in my F2 bottom end.
Cleaned the holes and went through them with a thread chaser. But the 2 middle holes in the front (exhaust side) lead into the crankcase..
How are you supposed to bottom them out if it's open? or does the hole get smaller in the bottom?

There is a thread here somewhere that lists the installed height of the cylinder studs.