Help- Tightened head bolt too much!

F

Fletchsd80

New Member
After having black stuff leaking out of either the head gasket, or the spark plug hole today when I got my engine running for the first time (probably oil although it was black like the grease?); I got out my torque wrench and tightened the head bolts to 13 pounds. A little while later I decided to try and up it to 17 just to be safe. One of them either stripped or broke off because it just turns endlessly now. I immediately lowered the others down to 15.

Does anyone know where I can get a matching bolt? Spookytooth has the entire head assembly, but I'd hate to have to pay for that when I just need the bolt. I will open it up tomorrow and see if it broke off or was just stripped.

Earlier when I took off the head, two of the bolts stayed in and the nuts came off, and two of the entire bolts came out with the nuts...is that supposed to happen? Are those broken as well? If they were broken I would assume that you couldn't tighten them when you put them back in?:-||
 
Sick bike parts sells a stud replacement kit.
There are two sizes 6 mm and 8 mm.
Or you can make your own using threaded rod purchased from Ace, Lowes.
I hope it just snapped off and did not strip the engine threads.

All of the nuts bolts and fasteners that came with your kit are really cheaply made..
The nuts and bolts holding my rear sprocket on.

Broke off one day. LOL
 
Last edited:
THanks Spad,

I went to try and get the head off, and that damn thing must be stripped because I turn it endlessly without it loosening! I'm at a loss now as to how to get the damn thing out of there? I have to get the head off or I might as well buy a whole new engine!

BTW I've had those sprocket bolts break on me too.
 
Last edited:
Were going to have to get you a smaller set of tools. If you can't get that stud out,force it upwards. Use vice grips if you have to. It will come out. I have the feeling you have those acorn nuts.
 
Last edited:
toytime said:
Were going to have to get you a smaller set of tools. If you can't get that stud out,force it upwards. Use vice grips if you have to. It will come out. I have the feeling you have those acorn nuts.
Click to expand...

I do have the acorn nuts, and when I could barely grab a hold on it with the pliers to try and lift up on it, the acorn part (round top) came off. So now I just have a regular nut that won't come off. I can't tell if the post is turning with the nut or not. It would be great if all it was was a stripped nut and not a broken or stripped post.

I am not very mechanically knowledgeable as far as tools go. So I need vice grips? Anything else? If I force the whole post out, won't I definitely strip the engine threads?

Thanks
 
to repair stripped threads in the block you can use a device called a helicoil thread repair kit sold at most auto parts stores should have them for metric and american the directions are in the kit or if you want to replace all the studs with american you can tap the block for the american thread
 
It sounds as if the nut may have stripped. I only say that because you say it turns but won't come off. It should be so easy for you to see what is turning. Use a wrench so that you can see the parts as you turn. This can be fixed so don't worry. Do you own a set of vice grips?
 
toytime said:
It sounds as if the nut may have stripped. I only say that because you say it turns but won't come off. It should be so easy for you to see what is turning. Use a wrench so that you can see the parts as you turn. This can be fixed so don't worry. Do you own a set of vice grips?
Click to expand...

The head is still on because I cannot get that nut off. I can't see if it is turning the post with it because the washer and lock washer are in the way and it is not high enough up to see the post. I don't own vice grips, and I cannot grab the post at all.
 
Norman said:
to repair stripped threads in the block you can use a device called a helicoil thread repair kit sold at most auto parts stores should have them for metric and american the directions are in the kit or if you want to replace all the studs with american you can tap the block for the american thread
Click to expand...

That's good to know thanks Norman! Now at least I know I don't have to order a new engine. I stil need to get that nut off though. I'm thinking of just taking it into a machine shop. Maybe I can get the threads fixed in the block if they are damaged there as well. I have no idea what they would charge for that.
 
Yes we sell a full kit like this:

Sick Bike Parts

So the nut spins on the remaining stud, but won't even come off? Wow that be stripped. A couple things come to mind since you can't get a nut splitter in there. Easiest would be to remove all the other nuts, have a buddy pull up on the cylinder while you turn the wrench in the reverse direction....this should put enough pressure under the nut to get it off. If that doesn't work, grind the nut off with a moto tool....or grind slot in the top of the stud and use a big screwdriver to take the stud out.

Indeed our studs are high grade 8.8 and nuts are good quality to prevent this hassle.
 
Pablo said:
Yes we sell a full kit like this:

Sick Bike Parts

So the nut spins on the remaining stud, but won't even come off? Wow that be stripped. A couple things come to mind since you can't get a nut splitter in there. Easiest would be to remove all the other nuts, have a buddy pull up on the cylinder while you turn the wrench in the reverse direction....this should put enough pressure under the nut to get it off. If that doesn't work, grind the nut off with a moto tool....or grind slot in the top of the stud and use a big screwdriver to take the stud out.

Indeed our studs are high grade 8.8 and nuts are good quality to prevent this hassle.
Click to expand...

That is a good idea thanks. My main problem is that I don't know if the post is turning with the nut or not because I can't see it. Last time I opened the head, a couple of the posts came out entirely with the nuts. I don't have a grinder so I think I will take it to a machine shop.
 
I can say with 90% certainty the stud/acorn nut interface is stripped - at least in my experience this is the fail mode - try the cylinder yank and crank procedure, it's cheap enough.....then evolve to grinding if that fails you.
 
Do you have a drill or hacksaw? Even just a hacksaw blade?
You have to learn to fix your own stuff and this is so easy.
You could slice a slot in the nut from the top with a hacksaw blade.
 
Last edited:
toytime said:
Do you have a drill or hacksaw? Even just a hacksaw blade?
You have to learn to fix your own stuff and this is so easy.
Click to expand...

I do fix my own stuff when I can. I replaced the mounting posts with all thread and used my hack saw to cut it to size. Initially I was thinking there is obviously not enough room to get in there with a hacksaw, but now that you mention it again I suppose I could go straight down on it.
 
Pablo also had a good idea about pulling up on the head as you turn the nut. The nut will catch the threads and unscrew. Don't bend the head though, lift up.
If you use a hacksaw blade, do as you said and if need be you could slice it down enough that the nut can be removed by destroying the nut with a screwdriver.
I wasn't trying to put you down, I was just saying that you should do it. Sorry if that came out as a put down.
 
No worries Toytime I didn't take it that way.

So I did what Pablo suggested and it came off easily! It is just the top of the post that is completely stripped where the nut screws on. So now I'm wondering if I should buy a new assembly online or try and figure out how to re-thread that top part while it is still in the block, and then try and find a matching acorn nut locally somewhere. I think the nut may be my largest obstacle to be honest. Where do you suggest I go from here?

Now that I think about it I could just grab the non threaded part of the post and try and screw it out that way so I wouldn't have to thread it while it was in the block. Since two of the other posts come completely out when I unscrew the nuts...I could take one of them along wit the stripped one into a machine shop and have them do it. I know Toytime, I should do it myself :), but I have been working on this thing so long that I am so anxious to get it running right ASAP.
 
Last edited:
Hi, And Welcome. Rethreading The Top Of Stud Is Not The Way To Go. Imho!! If The Head Studs Are What Came With The Motor, This Is A Great Time To Go To Better Quaility. Sick Bike Parts Has A Kit For About 10 Bucks (4 Studs And Nuts Etc.) What Size Are They, 6 Or 8 Mm. Have You Seen Their Shifter Kit Video On Their Web Site? Ron
 
Ron,

Thanks...I just ordered a new plug wire, carb o-ring, head assembly, and replacement engine bolts etc. My clutch cover screws are really stripped so I figure I'll just replace everything with quality parts to avoid future hassles. I checked out the video too BTW- pretty sick but right now I just have a one speed.
 
You must log in or register to reply here.
Back
Top