broken head bolt

[betag2]

1988 70 Yamaha. Well I did it. Broken the number 12 head bolt in the head(last one to come out). It broke with about 3/16" sticking out the head. Does anyone have any sugesstion.

 

[robnik1]

Re: broken head bolt

Drill it , easyout it(screw extractor), then a little heat. Maybe use some penatrating fluid before you start.<br /><br />So Close But... <br /><br />Lots Of Luck

 

[betag2]

Re: broken head bolt

hey, thanks for the reply. How safe is putting heat on the block when it's so close to the cylinder. Will it damage the cylinder wall? What about easyout since the bolt broke, I probally have a good chance of breaking the easyout? Or How about drilling it out in stages and then retapping? Isn't this fun!!!!

 

[pine island fred]

Re: broken head bolt

been there. the easy out will probably brake. do some homework and find a machine shop that can burn the stud out with a laser. an aircraft fixed base operator could steer you in the right direction. now that you are this far DO NOT try to remove the 12 or 14 bolts that hold down the exhaust cover.

 

[rodbolt]

Re: broken head bolt

hello<br /> you can weld a nut to the stud or just drill it. if you can get a drill to it just drill and tap it. welcome to saltwater corrosion

 

[murphy1]

Re: broken head bolt

well, if it makes you feel better. I had to replaced the exhaust gasket. I broke 3 of the 15 bolts. In one hole I broke an easy out, so I drilled it out to retap and broke the tap in there. Now I have a tap stuck in there and a gasket that's still leaking, oh boy!! I was talking to one suzuki mechanic (retired) that got out just because he was sick of dealing with suzukis fragile bolts. He said a simple replacement would always take a great time longer just because bolts always broke.

 

[jim dozier]

Re: broken head bolt

Betag2 if as you say it was the last bolt on the head you can now remove the head by tapping with a rubber mallet and let it slide off of the broken bolt shaft. There may be some resistance due to corrosion along the length of the bolt shaft once you break the seal of the old head gasket. Once you succeed in getting the head off you will have a nice long stud to get a grip on with a good set of large vice-grips. Application of heat with a propane torch to the shaft will help.<br /><br />DO NOT use easy-outs. They will break in marine use because the grip of corrosion on the bolt often exceeds the torque limit of the ez-out. They are great on cars or maybe freshwater motors, but not saltwater motors. See below.<br /><br />Murphy1 you can remove the broken tap by purchasing a carbide tipped tile grout remover bit (or some other similar carbide tipped bit) for a Dremel Mototool. With a delicate touch you can probably gently chew the remnant out of there and then you can drill out the hole and install a helicoil

 

[betag2]

Re: broken head bolt

rodbolt,<br />what do you mean by welding a nut to the stud? Is this to be able to turn the stud again with a wrench? How do you feel about putting heat to the that area on the block inorder to remove the stud?<br />thanks

 

[murphy1]

Re: broken head bolt

Betag2, what is a helicoil? the broken tap is on the top of the block, so I was think of cutting/grinding out and then filling it in with that 'durafix' product and then drilling and tapping a new hole. Has anyone tried that product? I bought it, but haven't tried it yet.<br /> http://durafix.com/

 

[jim dozier]

Re: broken head bolt

Murphy1, just install a helicoil. You buy them at NAPA or other auto parts stores. Using a specified (slightly larger than the bolt) drill, you drill out the damaged threads. Using the tap supplied in the kit you rethread the hole (slightly larger than the original hole). Then you screw in the helicoil which is a stainless steel coil that becomes the new thread. Now you have a new set of threads, stainless steel to boot.<br /><br />Once you get the broken tap or ez-out removed drill out the remainder of the broken bolt starting with a small drill bit. Use a center punch to keep it centered. Gradually increase the diameter of the drill till you get to the final one specified for the helicoil.

 

[Yepblaze]

Re: broken head bolt

It is quite common to take a slightly oversized nut and slip it over the existing portion (can also be used if broken flush) then by welding the broken bolt to the nut, you not only get a second chance to screw it out, but have also applied enough heat to the fitting to help release the corrosion. It can help to quench with penetrating oil while it's still hot.

 

[rodbolt]

Re: broken head bolt

heat is your friend<br /> use it<br /> use a lot of it<br /> good luck and keep posting

 

[betag2]

Re: broken head bolt

HEY YALL<br />How reliable is a helicoil on a head? I tried everything from penetrating oil to heat and still broke two easy-outs. I was able to remove the easy-out and drill the hole until I can start to see the threads. I don't want to drill any large until I know what size of helicoil to put in. Is this common to happen? I do live in southeastern Louisiana, plenty of saltwater. You know all this work and I still have to figure out why the thing is overheating. I hope it is the head. It had a ton of debris in it. All this for a few fish. Man, I'm having fun now!!!

 

[rodbolt]

Re: broken head bolt

if done properly heli-coils are wonderful.<br /> good luck and keep posting

 

[jim dozier]

Re: broken head bolt

Helicoils are equal to or better than the original threads. This is just my opinion, I'm not working for them or selling them. They have been around for decades. You buy the same size helicoil as the original head bolt and you use the original head bolt (in your case a new one since you trashed it) in the helicoil. Once its in you will forget which one it is. I have 3 in my cylinder head.

 

[betag2]

Re: broken head bolt

Thanks to everyone who replied to this message. I had an overheat problem at high RPM. I replaced water pump kit and thermostat still overheating. I removed head and broke headbolt #12, bolt on the bottom of powerhead. I removed the rear cover latch and was able to use long drill bits to drill out the bolt. I installed a helicoil and cleaned a ton of debris out of the head and headcover. Everything is working fine now, keep yall fingers crossed.Again thanks for all the help this is a great web site.