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Hello all,

Looking for advice on how to remove a broken head bolt on this engine. It's broken inside the block. I'm pretty sure someone over torqued it and broke it because all the other head bolts were torqued way over spec. Spec is about 18 foot lbs, these were torqued to about 60. Hopefully the head isn't cracked.

Is it worth trying a bolt extractor? I hear there is a good chance of them breaking too and then you have a bigger problem.

Thanks for any advice.

Nick

WELCOME to these Forums...

There are several ways to do it... BUT none are Easy to get Out...
Start with lots of PB blaster then try one of the various methods you can find on youtube... Here is one. https://www.youtube.com/watch?v=0iyJtGNemq4

Take your time use penetrating oil (NOT WD40) and with the right size Left hand drill bit & a Little luck you may get it... Like I said it is not going to be Easy... I have removed Many... some that were in locations that I could only use mirrors to get a good view, so it is not impossible... Just a bit challenging sometimes.
BTW, post back with your outcome and some pictures if you can.:smile:KennyV

Take your time and drill and use a set of Easy/Outs, DO NOT DRILL INTO THE THREAD.

start small because I find broken head bolts come out easy. Vey first thing just try a sharp punch and hammer and see if it will turn out. if not, next step drill a small hole all the way through the bolt and try again, if not, try a easy out but you will also need to drill the small hole to fit the easy out. just don't get strong and beak off the easy out. if not you will have to drill out the complete bolt threads and all and buy a thread repair kit which will be you last resort.

Ok, you all have convincee me to try it myself. I'll order the head gasket and new bolts and be back with a progress report sometime in the near future. I've a Wheel Horse carb I'm fooling with too; always something.

Cheers,
Nick

Try removing the bolt before ordering all of the other stuff, but you will likely get it out if it was broke by over tightening, they sometimes can easily be
brought out with a little bit of fiddling with.

I already ordered the parts. No worries, this gives me an excuse to get after the carbon deposits as well. It looks pretty black through the spark plug hole.

So you are saying you haven't even removed the head yet. To remove the broken bolt you will have to remove the head. No wonder you can't remove the broken bolt. With the head on how do you even know how the bolt is broken off. Once the head off it might just turn out with your fingers?

I use a reverse drill bit that way your drilling the hole counterclockwise and the easy out works a lot better. And less risk of it breaking.

I thought the head was removed too. Take the head off then you can probably turn it "gently" with Vice Grips. Try tapping on the end of it with a hammer to knock the threads loose. Don't put the monkey grip on it and wring it off flush with the block. You probably have enough of the bolt above the block to turn it out.

The head is not off but it's quite easy to see the break is inside the block.

NickR said:

The head is not off but it's quite easy to see the break is inside the block.

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Well this is a new one on me that I never tried to remove a broken head bolt with the head still on. Personally I really don't think its that bad of a job to remove the head. But seeing that is the way you want to remove this bolt I hope you the best of luck. Maybe the reverse drill bit, but be sure you use a centering punch and with a lot of luck just maybe you will get it out with out doing a lot of damage.

Before you try to muscle those over-torqued head bolts out, take a flat punch and hit center on each head bolt a few times to jar it loose. They will come out a LOT easier that way. If you can put some penetrating oil on them I would, but since they're so tight I doubt if much if any would get down into the threads. Loosen a small amount, then re-tighten just a tad back and forth and loosen them up like that, then they should come on out. But just trying to man handle them on out with a socket or wrench might wring off a few more besides that one. Good Luck with it. :thumbsup:

Not sure how I confused everyone, but, here is the skinny. I am not trying to remove the broken bolt with the head still on. I'm waiting for a new head gasket to arrive before I remove the head. I was able to remove all of the other head bolts, just haven't pulled the head yet. I'll give you a progress report next weekend.

Thanks all.

NickR said:

Not sure how I confused everyone, but, here is the skinny. I am not trying to remove the broken bolt with the head still on. I'm waiting for a new head gasket to arrive before I remove the head. I was able to remove all of the other head bolts, just haven't pulled the head yet. I'll give you a progress report next weekend.

Thanks all.

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Well I thought the head was off till you said it was still on. So just a matter of lifting the head off the block. Just why wouldn't you remove head so you can see what is involved with ordering parts. I always take something completely apart before I order parts so I only have to order them once and even at that I might still have to order something else. But also I am doing it to make money and looking and chasing for more parts cost money.

Had this happen on my mower this past spring. I used a cobalt drill bit based on the size I needed for the extractor (it was a Ryobi spiral extractor). I first smoothed the surface with a Dremel. Tapped the center with a punch and drilled an appx 1/4" deep hole.

I ended up having to hammer the extractor into the hole. Once I did that the bolt came right out. The bolt is actually still on the extractor.

In my case, I was the one who broke the head off. Learned a valuable lesson about click type torque wrenches. Mine came out pretty easily most likely because I'd coated the threads with Loctite blue before tightening them up.

I finally got to the bolt this weekend. I bought the cheap left handed bits at HF. As soon as I started drilling with the smallest bit I could see the bolt move. When I started drilling with the next largest bit it screwed the bolt right out of the hole. I guess I got lucky on my first, and hopefully last, broken head bolt. I de-carbed the head, piston and valves while I had the head off.

Now to get this thing running right. It starts right up but is missing and the governor is surging. Spark plug is new. Pulled the bowl and needles and sprayed with cleaner and compressed air. Needle holes are clean, still runs poorly. Guess I'll try pulling the carb and doing a proper rebuild. Finger crossed, I need to get some tilling done.

Thanks for all the help!

If the engine is surging concentrate on the low speed jet when going through the carb. repair.

Have you tried adjusting the mixture screw? Sounds like it's not getting enough fuel which is one reason it is loping and surging. Sometimes carbs can be a real pain to get adjusted, and some mechanics simply replace it. Chain saws seem to take some of the worst punishment on dirt and oil around the engine and carburetor , cooling system!

I have tried adjusting the high and low jets and made sure they were clean and undamaged. I've pulled the high speed assembly and made sure the tiny metering holes were clear. I've sprayed through the needle seats and up through the inlet seat and fuel line connection. So, I'm to the point of pulling the carb and doing a full scale cleaning.

I pulled the carb and decided not to clean it since it had some corrosion. I installed a new carb and the surging is gone and the motor idles fine, but it is still missing when I advance the throttle. It's sort of a random missing, a popping sound. This motor has a solid state ignition module. The plug is new. Any ideas on what I should check?

Thanks all.

NickR said:

I pulled the carb and decided not to clean it since it had some corrosion. I installed a new carb and the surging is gone and the motor idles fine, but it is still missing when I advance the throttle. It's sort of a random missing, a popping sound. This motor has a solid state ignition module. The plug is new. Any ideas on what I should check?

Thanks all.

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What type of fuel are u running how old is the fuel is there water in the fuel ...Check the flywheel key that's where i would start

The fuel is fresh, ethanol free and mixed with Sea Foam. I'm afraid you're over my depth now. What do you mean by check the flywheel key?

Adjust the carb so its a little richer, or check the valves.

NickR said:

The fuel is fresh, ethanol free and mixed with Sea Foam. I'm afraid you're over my depth now. What do you mean by check the flywheel key?

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there is a fly wheel under the cover on the top take the nut off and make sure its not off set if it is off just a hair sometimes it will cause this prob ...And as Engineman stated check your valves also as for adjusting the carb if read it properly u have tried to adjust it already