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'83 Johnson 140 V4 - One of the head bolts snapped and a small amount of water is leaking out. I need some advice on how to fix the problem without screwing up something else. Thanks
Hate to be the bearer of bad news, but you're probably looking at a project. Best case, you pull the head and have enough exposed bolt to tap an appropriately sized stud extractor over it. Then with much patience, penetrant and selective heating of the surrounding block, you hopefully crank out the remaining portion of the bolt. If the stud is broken flush, then you have to drill into the bolt and insert an extractor.
If this fails, you then move on to the heli-coil phase of your project, which requires overdrilling the bolt, tapping new threads and inserting a repair thread (the helicoil). Not fun, given the possible outcome. If you run off-center, as the repair will exceed the value of the engine.
You may actually want to check out a shop and see about having it done. Although, given the age of the engine, this may be a good opportunity to get your feet wet.
Managed to snap off a bolt while replacing the thermostats on my Johnson 200. Not the head but really close to it. I ended up going the Helicoil route. It worked great but I had help. I measured the hole spacing on thermostat bolt pattern very carefully, made a drawing and paid the machinist at work a bottle of booze to make me a jig so I didn't get "off center" while poking holes. The jig was nothing more than a 1" thick piece of steel with clearance holes cut on the thermostat bolt pattern centers. I bolted the jig down with the good holes and used the clearance hole over the snapped bolt to guide the drill bit. Even with this help I needed a good chug of pepto afterwards.
If you try and drill it out yourself go SLOW and use lots of cutting oil to keep the bit cool. If you heat the snapped bolt up and harden it you will be seriously screwed.
I'm only asking a question, not question your suggestion. Can a heli-coil take the torque of a head bolt? What would be the torque of a head bolt be on a 83 140 V4, 75-90 ft. lbs?
jay hunt 3,
For starters, Welcome to the forum.
If this bolt that you snapped the head off of is exposed to the ambient elements (but still under the cover), you probably are looking at a 98% or better chance that the bolt is corroded itself to the head. If this has happened then you are looking at a world of hurt - sorry man. Even if you remove all of the other head bolts, chances are there is two alignment pins for installing the head gasket and head to the block that will deny you from spinning the head evem if you were able to crack it free and had the room to spin it. I think you are going to have to dissolve the corrosion first before you attempt to crack the bond between head and block. If you don't deal with the corrosion first I feel you run a strong risk of damaging/ cracking the head.
Have you removed all of the head bolts? Have you tried to break free the head from the block with a block of wood and a mallet?
So long as the water is just leaking out, you will be ok - there is plenty more where it came from.
Seems to me you need to pull the head and find out whether you have a bit of bolt to work with. You might be lucky enough to be able to cut a slot (with a file or a Dremel) and use a screwdriver. Otherwise, see if you can't get it out with a good screw extractor for your drill and some Liquid Wrench.
Does anyone know whether the block or the bolt will expand more when heated?
Also, is there anything better than Liquid Wrench to penetrate and loosen the bolt?
If this bolt that you snapped the head off of is exposed to the ambient elements (but still under the cover), you probably are looking at a 98% or better chance that the bolt is corroded itself to the head. If this has happened then you are looking at a world of hurt - sorry man. Even if you remove all of the other head bolts, chances are there is two alignment pins for installing the head gasket and head to the block that will deny you from spinning the head evem if you were able to crack it free and had the room to spin it. I think you are going to have to dissolve the corrosion first before you attempt to crack the bond between head and block. If you don't deal with the corrosion first I feel you run a strong risk of damaging/ cracking the head.
I imagine this is a relatively recent occurrence (say in the last month or so) because he only could run the engine so long without further problems, so perhaps there is only a little bit of corrosion to deal with. You make a good point, though, about the possibility of not being able to get the head off. That would say the extractor may be the only option short of the helicoil.
I imagine there is some chance the head bolt deformed when it snapped, which might make anything short of overdrilling and re-threading impossible. I wonder how much we are looking at for this?
If you use a screw extractor on it, be extremely careful. There is considerable risk that the extractor may break off...in which case you are in real trouble. A broken off hardened steel extractor is almost impossible to drill out. Skip the hardware store variety extractors. Go with an industrial quality extractor like those at http://www.mcmaster.com . See catalog page 2674 for a "one step drill out extractor" or page 2673 for a "multi-spline extractor".
There is another way to attack the problem that is often successful. Centerpunch and then drill the center (as close as you can to it) of the broken bolt with a small drill bit, titanium coated or cobalt bit recommended. Incrementally enlarge the hole with bigger bits until you have drilled away most of the bolt out to the threads. But stop enlarging before you drill into the threads. Once most of the bolt is drilled away, what remains is weak. You can use a hammer and a sharp punch to collapse what's left into the center, and then pick it out. Sometimes the remains will just screw out. If the threads in the block are slightly damaged in the process, you can clean them up with a thread chaser, and use some lock-tite on the new head bolt.
Garret,
Good point about torque requirements. I don't know the torque requirements for this head, but a helicoil is a fairly common repair for head studs as they are so easily fatigued and prone to failure.
Jay,
I also forgot to add, that you may be able to wriggle out of this if you have enough exposed bolt remaining and someone handy with a welder, you can tack on a nut to the top of the bolt and work it out, again with penetrant and heat, and some careful impact (I have a 3/8 drive hand held impact wrench for this application - tap w/hammer while twisting) and again much patience. Use lots of penetrating oil, lots of time and easy on the heat and impact or risk shearing the rest off. You may also elec to tack on a pair of vise grips, if the circumstances allow it. You may have to reapply & soak over a couple days before it breaks loose, if at all.
I would opt for the extractor as a first alternative.
I'm thinking the screw extractor approach will be of little gain, here's why. I know in the automotive world head bolts are L8 quality = very strong bolt and very difficult to break. I am "assuming" the marine manufactures would use the same quality of head bolt.
Now if jay hunt 3 snapped just the head off the bolt, that would mean to me that the bolt is like welded in with corrosion, hence no extractor alone is going to break that puppy free, you'll just break that extractor and that's a given. He has to eliminate that corrosion if it's there.
Now if the bolt broke off somewhere along it's shaft; does the shaft of the portion of bolt that broke off show any signs of corrosion? If not, then he might be able to drill, install a top quality extractor and heat the block up and try to extract the broken bolt. In cases like this, I always like vibration. Sometimes hitting the shaft of the broken bolt with a drift and hammer or a pneumatic impact hammer and dimpling bit can break the bolt's hold, other times it does nothing, but you have to try.
Frank007,
Both the block and bolt will expand if the heat is applied in the general area of the threaded portion on the bolt. Generally when this method is applied, what you do is apply enough heat to the area surrounding of the bolt to get it pink to red, then you quickly cool the broken bolt with a cold wet cloth, strike the remaining broken portion of the bolt to send a shock wave through it which will aid in the extraction.
***** Now a word of caution: If heat is used to make the metal pink or red and you do get the head off/ bolt out, let the metal cool gradually on it's own. Then check the face of the head and the deck of the block for flatness. If you do not have an "accurate" means for checking these surfaces take the engine and head into a machine shop and have them check it. Either or both of these surfaces "can not" be warped.
Now if the block or head is aluminum be extra carful with the heat. Here you "must" accurately check for warpage.
Also, is there anything better than Liquid Wrench to penetrate and loosen the bolt?
I've had good luck with PB Blaster.
Did the bolt break during disassembly, or re-assembly? I've had almost no luck extracting broken bolts that have occured during disassembly. Bolts broken during re-assembly (as a result of being over-torqued) I've always been successful using an easy out extractor. The key to success with and easy out is drilling the hole properly (straight, proper diameter, and depth) into the center of the broken bolt. And the key to drilling the hole is an accurate center punch, sharp bit, and cutting oil.
As IT wonder mentioned, if the extractor breaks, you've got problems.
If you can't extract the bolt, but are able to drill out the bolt, then a Heli-Coil is the way to go.
__________________ Grady White SeaFarer 226 w/Yamaha F225 - SOLD
How much water is escaping? Maybe it can it be run as is to squeak out another season or two from this old gal while you save up for something a tad newer.
I think only a little bit is leaking, but he has two concerns: (1) Is the water getting somewhere it can create a major problem (or could it do so in the future), like into the cylinder? and (2) If he just keeps running it, will he have a significant, sudden problem at a bad time, like the head gasket being blown completely out at the spot where the bolt is snapped while 10 or 15 miles from port? SeaTow is one answer, but he has to weigh how much he could push it and what the consequences could be.
What do people think about just continuing to run it a season or two longer? Is a compression check to make sure the affected cylinder(s) are not more than 5-10% different enough comfort to continue running it?
A heli-coil will work but the key is to do as mentioned and try to drill it out or extract it normally first. First try to grip it with a set of vice grips. If that doesn't work, then cut on the exposed head to make a flathead type slot and try to get it out with an impact screwdriver (the type you strike with a hammer). If that doesn't work it seems like a lost cause from the get-go, start with a smaller sized GOOD drill bit and drill down a 1/4 inch or so. Then try to use a stud extractor. You might want to try to apply heat (torch) to the block to get it to expand larger than the stud itself, but the stud will eventually heat and expand also, so you have to work quickly.
Heli-coils will work fine though, they use them on cars all the time and as a last resort after trying the above. I recommend that you have a pro do this..
Oh yeah, make sure to keep soaking that dude with liquid wrench and let it penetrate for hours..
Good luck,
Chris
__________________ - Chris
Guess What?? I got a Fever.. And the only prescription is.. MORE COWBELL!
-2011 Blue Wave 2400 Pure Bay / Yamaha F300 4.2 with Command Link Plus
-2003 Sea Fox 195 Bayfisher - Mercury 125 Saltwater Classic (Sold)
-1994 Wellcraft V-20 Step Lift (Sold)
Thanks everyone for the suggestions. The bolt snapped sometime after being tightened. It was not during assembly or disassembly. The bolt came out clean and snapped at the threads. I am not sure whether any will protrude from the block. The leak is a small drop every 5 seconds. If the compression remains good on the two cylinders what will the consequence be of continuing to operate the motor without replacing the head gasket?
For starters: although not many people do, all bolt, nuts and studs should be replace every time the engine is ripped down. Here is a prime example of why.
Quote:
The bolt snapped sometime after being tightened.
Do you have any idea how long after? Are we talking weeks, months, years? If it wasn't to long ago (weeks) I would be getting the head off pronto so I have a fighting chance at using an extractor to back out the broken bolt - the longer you leave it the harder it will be to remove.
What are the consequences? Try water in the cyclinder and blowing a hole through the top of the piston with possibly taking out your bottom end as well as posssibly putting a rod through the side of the block. On a lighter side, warpping the head and block deck.
Pull the head and see if you have bolt any portruding from the block. If so, thread a properly sized nut on as far as it will go and have the nut tack welded to the bolt. Saturate it with PB Blaster for a few days before you slap your wrench or ratchet on the nut and try to spin it out. The imporant thing is to not let too much heat build up while the weld is made.
This will be much more likely to succeed than trying to cut a groove for a screw driver.
But if it doesn't work, you haven't really lost anything. You can still attempt a screw extractor or drill it out.
If you have access to a welder: get a nut that is slightly smaller than the size of the stud that is broken off flush. Put it on top and weld it to the stud that is stuck. You should be able to back the stud out. The weld is ussually stronger than the material that you are welding. Be careful not to over do it though. Just use tack welds as to not heat the block up that much.
I have done this job twice in my life, once on an old outboard and once on an aluminum headed car exhaust manifold bolt. With care you can have good success. A couple of thoughts:
1. Use the best drill set you can buy, no cheap stuff.
2. The center-punch and first pilot hole is critical, ensure as close to center as possible. Drilling straight is also just as critical.
3. As previously mentioned, use the best extractor set you can buy.
4. DO use heat, the head is aluminum alloy,the bolt is steel. Aluminum expands much faster than steel and using some pin point heat around as much as the threaded hole as you can get to helps LOTS. Heat is an outboard mechanics friend for loosening tough bolts. Shop mechanics use heat all the time, it works.
Take your time and it will come out OK just ensure the drill hole is as close to perfect as it can be. I would have a strong concern with water being able to get into that cylinder right now, just as it is leaking outside the gasket, it can and often does leak inside. If you are concerned with damaging the head or haven't done precise drill work before you could find a good machine shop that has the right stuff but it still remains a tricky job because it's not something they can chuck up in a machine and precision drill. Most machine shop guys are pretty good at figuring out how to make a quick guide to assist as someone mentioned but their real advantage is having the best drills and extractors. It may be less expensive to find a machinist that will do it than it will be to buy the right stuff yourself. Good luck.
Snapped Off Head Bolt 
