Head Stud Question

pucksterpete

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:confused:Newbie question. I have 66cc Grubee Skyhawk and I am in the process of switching the acorn nuts on the head studs. Could someone tell me what type of thread I have on these studs. (See Pics) The thread is different from any remaining studs on this engine. My basic problem, I live in France and our local home depot doesn't have the correct thread on their lock nuts. If anybody could share some light on this I would appreciate it.:bowdown:

Thanx,

Pete
 

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:confused:Newbie question. I have 66cc Grubee Skyhawk and I am in the process of switching the acorn nuts on the head studs. Could someone tell me what type of thread I have on these studs. (See Pics) The thread is different from any remaining studs on this engine. My basic problem, I live in France and our local home depot doesn't have the correct thread on their lock nuts. If anybody could share some light on this I would appreciate it.:bowdown:

Thanx,

Pete

They are either M8X1.0 or M8X1.25. They sorta look like 1.25, but I would be amazed if you didn't have those in Fronce, because M8X1.0 is a bit more rare. I say look elsewhere than HD.
 
Pete, I'll agree with Paul in the fact that the MOST common 8mm thread is going to be 1.25. To add to that the only thread a 6mm comes in is a 1.0 Take a 6mm stud (a screw from the clutch cover will do) and overlap it on the 8mm stud (thread on top of thread). If the threads fit perfect then it tells me they are both a 1.0 thread. If not then the 8mm stud is a 1.25 Having said that I'd recommend that you change out both studs and nuts, not just the nuts.
 
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Well here is what I got

I guess I have 8 X 1.0mm studs (see Pic for overlapping stud threads). I went to this large home depot like store (Castorama) here in France the other day and bought 2 types of nylon locking nuts (2 diff sizes). 1 type for the front & rear mounts, exhaust & intake studs, all fit fine. The 2nd type for just the head studs. The only ones that do not fit are the head studs. The nylon locking nuts are the same drive for the ratchet 13mm as with the acorn nuts, but the threads are different. So, I assume that the nylon locking nuts I bought for the head studs are 1.25mm, would this be correct? They did not have any other type of nylon lock nuts. Thank you :bowdown:, to the three of you for your help in this matter. Now, I must find a store that will have what I need. To Pablo, can't wait to install the shift kit, it should be arriving here any day.

Thanx,

Pete
 

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Correct 1.0mm

You guys are correct the studs are 1.0mm I had to go to a bolt & nut distributer 15km away in another town to get the correct Nylon nut (see pic). No one around here in Corbeil or Evry, France had it. What a pain in the a s s. So, I plan on using blue 242 loctite, washers (where needed) and nylon lock nuts on the front & rear studs, head studs, exhaust and intake studs.

What about using blue 242 loctite to the clutch cover bolts and clutch arm cover and anything else that might need it?

Thank you again for all your help. :bowdown: I just want make sure I have this engine prepped before I mount with shift kit.

Thanx,

Pete

Also, from what I can tell every stud sticking out of this engine and even the bolts for the clutch cover etc are all 1.0mm thread. France's 2 large hardware stores that I went to carried the 6mm X 1.0mm nylon locking nuts, but for the 8mm it was 1.25mm thread. Why wouldn't they carry the 8mm in 1.0 thread? Just doesn't make sense.:rolleyes:
 

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Out of the box, I replace the OEM hardware, with a grade 8.8. The OEM junk is around a 3 and the problem can be that they will stretch. They can't seem to take the torque that the cast aluminum can. The problem with the proper torque, in this case, is dependent on the cast not the stud when up grade is made. The 8.8 will take more torque then the case will. Hardware I replace...Cylinder studs, engine mount studs, exhaust studs, and although not needed the intake...that is all. The clutch cover, drive gear cover, and the magneto cover have screws that I just tighten by hand. I use (in my case) red lock tite on all replaced studs..none on the others seem to be needed. But if you do, yes blue. 6mm torques between 50 and 60 INCH POUNDS..I use 50 and just for the record 150 to 200 INCH POUNDS on 8mm and I use 150. NEVER had a stud strip, stretch, or loosen up. All my studs have either double locking nuts and or nylon locking nuts.

Might want to look at these pictures... http://www.motoredbikes.com/album.php?albumid=1018
 
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You guys are correct the studs are 1.0mm I had to go to a bolt & nut distributer 15km away in another town to get the correct Nylon nut (see pic). No one around here in Corbeil or Evry, France had it. What a pain in the a s s. So, I plan on using blue 242 loctite, washers (where needed) and nylon lock nuts on the front & rear studs, head studs, exhaust and intake studs.

What about using blue 242 loctite to the clutch cover bolts and clutch arm cover and anything else that might need it?

Thank you again for all your help. :bowdown: I just want make sure I have this engine prepped before I mount with shift kit.

Thanx,

Pete

Also, from what I can tell every stud sticking out of this engine and even the bolts for the clutch cover etc are all 1.0mm thread. France's 2 large hardware stores that I went to carried the 6mm X 1.0mm nylon locking nuts, but for the 8mm it was 1.25mm thread. Why wouldn't they carry the 8mm in 1.0 thread? Just doesn't make sense.:rolleyes:

I'm having a hard time trying to keep up with this thread.. In the first post you say that the cylinder studs threads are different .. that means the 6mm studs are 1.0 (as that is the only standard thread they come in, not considering a specialty cut) and that would make the 8mm a 1.25. Why would you be looking for a 8mmX1.0mm nut?? Are the threads on the 6mm stud and the 8mm stud the same or not???
 
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Out of the box, I replace the OEM hardware, with a grade 8.8. The OEM junk is around a 3 and the problem can be that they will stretch. They can't seem to take the torque that the cast aluminum can. The problem with the proper torque, in this case, is dependent on the cast not the stud when up grade is made. The 8.8 will take more torque then the case will. Hardware I replace...Cylinder studs, engine mount studs, exhaust studs, and although not needed the intake...that is all. The clutch cover, drive gear cover, and the magneto cover have screws that I just tighten by hand. I use (in my case) red lock tite on all replaced studs..none on the others seem to be needed. But if you do, yes blue. 6mm torques between 50 and 60 INCH POUNDS..I use 50 and just for the record 150 to 200 INCH POUNDS on 8mm and I use 150. NEVER had a stud strip, stretch, or loosen up. All my studs have either double locking nuts and or nylon locking nuts.

Might want to look at these pictures... http://www.motoredbikes.com/album.php?albumid=1018

Thank you very much for the insight on this. I don't want to ruin this engine because of too much torque or loose nuts & bolts. The pics have helped out tremendously for proper mounting.

Thanx

Pete
 
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