Mounting Studs Breaking Off

T

the-bike-guy

New Member
I have a question for all you experts. I have mounted a 48cc engine to a mountain bike. I have since broken 2 mounting studs off the bracket. They have broken flush to the engine block. Does anyone have any solotions on how to remove the broken studs and how to prevent this from happening again. This is the second time to break off. Once on the front mount and second on the rear mount. It was not from over tightening the studs because it happened over time of riding.

Thanks for your help in advance.
 
The proper way is to drill a small hole in the centre of the stud and winding an "easy out" into the hole. An easy out can be had for a few bucks. In the past I have managed to remove broken studs with a very sharp chisel or punch by tapping it sideways with a hammer, turning it outwards. Once it moves a little it will get easier and easier to remove enough to grab hold of it.
easy out tool - Google Image Search
 
Just noticed your from "The shwa". I'm just up the road in Lindsay. There is a great guy selling kits in your town in case you are interested. He even emailed me to ask if everything was all right.
 
Another way is to use a dremel tool with a small cut off wheel... make a straight cut across the broken stud tip, and use a small straight tip screwdriver to remove it. (^)
Also... stop over torquing the bolts!!
 
Be careful with the low cost easy outs. If you break one off, then you'll need a diamond bit tool (in a DRemel to get the piece off).

What you really need is a left hand twist drill bit (cobalt if you can find one), chucked in a reversible drill - drill (in reverse/left) into the center of the stud. Either you will drill into the stud, and/or it will catch and come right out.

Then, yes we do sell this:

SBP hardware kit

Eng-Hard.jpg
 
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All studs on all new HT engines should be replaced. Its a must do. They should have a tip for newbies that include great tips such as this and others....such as intake gasket replacement, replacement of spark plug with US or Japanese made one, loctite on everything, etc..etc... Many of issues posted on this site are repeat issues that could have easily been prevented if someone posted a great newbie build tipsheet.
 
The same thing happened to mine. After getting them out, bring the mounting allthread piece with you to a home depot. At mine they didn't have allthread, so I looked for a metric bolt that matched the thread and width, and dremeled it so it was about as long as it was origionally. It works way better than the thing that comes in the kit and I could tighten it as much as I wanted without worrying.
 
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