8 MM head cover bolts.

[BLEEDRED]

What is the porper torque for the 8 MM head cover bolts. The clymer had something like 33 which seems high. After the 440 project last year I stripped two of the 8 mm bolts and snapped one off. My head gasket ended up blowing out aorund the timing chain area. Don't want it to happen agian.

After this weekend it won't look like this anymore. I had to tear it apart to install HD head studs and inserts in the jug for the 8 mm head cover bolts...

[duke416ex]

I just always get the center bolt at 18 pds and then snug up the outer 8mm bolts. I have never had any problem with them backing out or breaking any.

[zephead400ex]

Snug + 1/4 turn;)

[khen]

I stripped one out when trying to torque them to the factory spec.. Now I just put medium hold threadlock on them and snug them up.

[blue416ex]

i have a question about these one of mine is just bouncing around in there and i dont know what to do i tried to tighten it and it is justsitting in there almost like it isnt long enough i havent taken anything apart yet in fear of not being able to ride it doesnt lkeak or anything this is on the valve cover not in the head im not sure what to do or if i should just leave it alone and not mess with it:confused: :confused:

[BLEEDRED]

Sounds like it is stripped. Depends on which one it is. Might just be best to leave it or now if you are not having problems. In the future if you get it the top end for a rebuild, cam, bore or what have you, I would fix it with an insert.

[blue416ex]

its getting a cam in about 2 weeks or so probably next week or so because i just want to ride it this easter break then it will be getting a stage 3 cam or the old stage to as i like to say but its getting cammed to match the 416 i just put in about 2 weeks ago but it was fine then just 2days ago i noticed rattling then saw the stud popping up tried to tighten it but its almost like its catching no threads and i can push it in until its flush with the valve cover im just wondering what will have to be done to fix it :ermm:

[BLEEDRED]

Where does that bolt thread? In other words, is it a short one long one or what? I would fix it when you cam it.

[blue416ex]

its a l o n g one lol its pretty long but its on the velve cover so i dont think it would be holding down the head or anything its on the right side of the quad when you are sitting on it

[BLEEDRED]

Yup I stripped that one too along with two other long ones on the same side that thread into the jug and help hold the head gasket down around the timing chain passage. My head gasket ended up blowing out right in that area. It's up to you, but in the long run you are going to be better off fixing it when you put the cam in. Actually on my first rebuild I stiripped that bolt first and then the other two when I took the head cover off to check the bolts on the cam sprocket. Good luck!!

[duke416ex]

I have that bolt stripped to, I just nticed it backed out the other day, i can still feel it grab threads though so maybe it just backed out. I wonder if that is always the first bolt to go?

[BLEEDRED]

That is exactly what was happening when I first stripped it. You could feel it grab the threads a little bit and then it would just turn. So it wasn't totally stripped, but not doing it's job either. Get it fixed.

[F-16Guy]

Originally posted by BLEEDRED
What is the porper torque for the 8 MM head cover bolts. The clymer had something like 33 which seems high.
Probably 33 in.lbs., not ft.lbs. You'll need a torque wrench with an inch-pound scale. Your local auto parts store would probably have one. If not, Sears will. It will probably have a range of about 20-100 in.lbs.

[cals400ex]

i am not sure where your getting 33 from? the cylinder head cap nuts and the cylinder mounting bolts are both 33. that would be way too much for the small 8mm bolts. there actually isn't torque specs for the small 8mm bolts. my manual says to torque the MIDDLE 8mm nut (in the middle of the valve cover) to 17 ft-lbs. however, i guess that is a misprint. that bolt is a 12mm bolt, not 8mm.

[MIKE400EX]

When they refer to an 8mm bolt (or nut), 8mm (or whatever size) is the diameter of the bolt, NOT the size of the hex head that you turn. You'll strip or break every bolt going by the head size. 5 ft-lbs. is plenty for those small cover bolts. I believe the center (larger) one is 17 ft-lbs. as Cal mentioned (it's an 8mm bolt but the head size is 12mm).

[BLEEDRED]

Yup I think I am just totally retarded then. I don't have my manual in front of me but the bottom line is that I trashed three of the bolts last year and it lead to a blowed up head gasket and hot oil shooting out the top end. But I've taken steps to correct the problem.

Moral of the story, do all of your research before you crack open the engine and don't be afraid to ask what might seem like stupid questoins on this forum...that's what we are all here for.

Thanks for the clarification guys and thanks for brining to my attention that I can't read and/or understand simple instructions. No seriously, thanks!! I'll take more time reading next time instead of hurrying the top end together so I can race out in the field and sling dirt. :D

[400exredrider]

Anyone Know the specs on the acorn nuts and the head studs?

[04EXdude]

WOW!.........Bleedred, your bike is clean! Do you ever ride that thing?

[BLEEDRED]

WOW!.........Bleedred, your bike is clean! Do you ever ride that thing?

Hell yes I ride it, but it's been in a heated garage torn down for two months and I have gone through the entire thing. It won't be that clean much longer.

[duke416ex]

I want to say the head nuts are like 33, do a search and you will find it on here somewhere.

[BLEEDRED]

I want to say the head nuts are like 33

Correct.