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Discussion Starter · #1 ·
Was sealing my engine cases, over torqued the first bolt and it snapped. The bottom of the screw made it to the other side, not sure if the threads are damaged. It was the center bottom front bolt- the bolt in the front registration dowel. What's the best method to go about fixing this? Should I get a left handed extractor and catch it from the other side? Does it need to be removed (since the registration dowel is around it)? Is there another solution?
 

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Is there enough on the opposite end to grab with vice grips? Personally I'd want it out - in part because I'm a neurotic lunatic, and otherwise because it'll be easier now than when you realize that you're leaking oil from that spot. If there's not enough to grab on the other side, you could always try a screw extractor - just go small enough to fit without hitting the threads, and be careful to not cut into the sides while you're giving yourself a pilot hole. If you can see the other side but it's not poking up enough to grab, it might be worth using a tiny cutting wheel (like a Dremel) to zip a slot into the top of it and screw it straight through with a flathead.
 

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What did you torque it to before it snapped?
I take it this is for the 350? You already sealed the cases?
If it were me, I'd pry the cases apart and remove it.
Give the extractor or reverse bit a go. If there's a recessed uneven edge the I might try and unscrew/tap it out with a nail and hammer.

Edit: not sure how other do this, but I lightly tighten all bolts, then tighten the larger diameter ones first(there's like 4 of them or something), then go around and do the smaller ones.
 

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100% agree. The little ones go in last for me, and are last to get snugged up. On the 360, they’re wimpy little suckers.

There may even be a tightening sequence in the FSM. Mama Honda knows best.
 

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Discussion Starter · #5 ·
It's for the 350, yah. I had the torque set at 12lbs, which is at the bottom of my range. It never clicked or I was just way out of it. Realized it might've been too much, then felt it snap.
The bolt is extruding pretty far. I didn't measure it, but probably 3-4mm. I'll try slotting the bolt first.

To be honest, this is my first time working on a motorbike. When the bolt snapped my reaction of comfort was to post here. Ha.

Here's the extruding piece of the bolt.
 

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The lower and upper 20% shouldn't be used on a torque wrench due to inaccuracies, IE; 0-100 torque wrench use only 20-80.
 

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I know that most here worry about using a torque wrench for most bolts on our engines as the FSM offers torque values for practically everything, but I learned long ago that many situations - particularly the 6mm variety - are simply tightened enough by using a good "feel" for both general tightness and the fragile nature of 6mm bolts on these engines. I've never used a torque wrench on 6mm bolts on engine cases, cam chain tensioner housings, torsion bar retention bolts, shift levers and many others... it needs to be tight, but not so tight that you risk damage, and if your torque wrench has an error factor that is more than you realize... you can get in trouble in a hurry. Obviously, the larger and more important bolts and cap nuts on lower cases and cylinder/head studs need to be properly tightened with a torque wrench as our ability to "feel" is more suspect as the tightness factor increases. I've never had anything go wrong while using that approach and after you work with the strength of Honda's 6mm bolts for a while, you develop a good feel for how much they can tolerate before either stretching them or breaking one off.
 

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6 foot pounds is plenty on a 6mm bolt. I have an old Craftsman 3/8s drive beam style torque wrench marked in both inch/pound and foot pound scales. Converting all the torque figures to inch pounds makes it feel more accurate (of course it makes no difference). My half inch drive torque wrench stays in the tool box until the axles need torqued.
 
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