I broke an important screw

I was putting a bi-turbo exhaust on to my Puch magnum mk11 (1979) and the screw that comes out of the bottom of the engine broke. It broke off flush only leaving 1/4 of an inch or less sticking out. How do I fix that? I can't even put my old exhaust on because there isn't enough screw left to make a seal.

Please help, my girl is out of commission until I figure this out, which leaves me with no transportation.

Thanks all!

Re: I broke an important screw

See Ya Moped Army /

The easiest approach is to take the cylinder off and bring it to a machine shop. They can remove the broken off stud for you.

Re: I broke an important screw

But where do I get a new one once the old one is removed?

Re: I broke an important screw

See Ya Moped Army /

They are easy to come by or you can even use a 10 mm bolt in place of the stud. Just make sure it isn't too long.

Re: I broke an important screw

John Joedicke /

Are they not 6mm

Re: I broke an important screw

Might be a number 6..but its a 10mm thread.

You can go to the hardware store and buy a removal bit for a drill. Then you have your buddy hold the bike up while you drill a pilot hole down the middle of your broken bolt head no more than 3/8 inch or so. Then put on the removal bit and drill it down into the hole you made. As you drill in the broken piece should thread right out.

You definely aren't the first person to do this. They make them too small in my opinion. Everyone I know who has worked on peds has dealt with this problem. Now you know to be real careful with those little suckers.

Re: I broke an important screw

So the easiest approach wouldn't be to take the cylinder off? All I need is a removal bit?

This exhaust has been bad news for me since I got it, starting with it being damaged in shipping and then the holes weren't big enough to fit the screws because they weren't cut right. So after I made the holes bigger the damn screw breaks off! I should have left my girl stock.

Thank for all the input guys, I really appreciate it.

Re: I broke an important screw

You like it better one you iron thing out...patience young grasshopper. With the removal bit procedure you will not have to remove the cylinder. Like I said...just have a friend hold the bike in a standing wheelie position so you can control your bits, it takes a steady hand. Use a point set to start the hole if you have to. Don't be afraid to ask the guy at the hardware store to explain how to use the removal bit.

Re: I broke an important screw

Believe it or not I already know how to use a removal bit. I just wanted to make sure that it was the best approach. Thanks again.

Re: I broke an important screw

actually what I did was remove all flamable pecies from around the bike, and took an oxyacyetlene (spelled wrong) torch and heated up the cylinder, then just took a pair off vice grips and threaded it out. that is, if there is enough sticking out to grap a hold of. and your cylinder must be cast iron.

Re: I broke an important screw

sometimes it's hard to get everything lined up perfect so nuts and bolts are not expected to cure a leak or an alighment problem... but it has to be done.

Re: I broke an important screw

Take the nut off the broken stud to the hardware store and try it on the bolts or studs to make sure you get the correct size.

Re: I broke an important screw

umm i donmt know if i read it wrong but this is all u have to do: take vice grip to the stud, spin it around and around untill it comes out (unscrew it)(it will take a while because it is long, then go get a new stud, it should be 6mm...takes about 5 mins ppl...the first time i broke a exaust stud i was buggin out cause i thought it was welded to cylinder..then i realized it wasnt and just unscrewed it

Re: I broke an important screw

See Ya Moped Army /

That's fine if there's enough of the broken off stud left to grab onto. But by her description, there isn't.

Re: I broke an important screw

No your right...I noticed just it in the first post myself. If there is a 1/4 inch sticking out, by god just grabb it with vice grips and turn left...geez.

Re: I broke an important screw

Don Pflueger /

that and it broke because it wouldnt turn to begin with.

Re: I broke an important screw

Allen Murphy /

Last one I had to do in a aluminum cylinder head was easy-goes like this:

Thread on a nut to WHATEVER is left-no matter how little.

Then, take an arc welder and weld the center of the nut to the remnant of the stud. This gives you something to hold onto, and conducts the heat down the stud, expanding it in the aluminum, and as it contracts, it breaks free of the aluminum-out it comes!

Works better than any removal bit I've ever used-even with the head locked in a vertical mill!

Al Murphy

Re: I broke an important screw

hmm.. i like that..

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