Engine Motor Rear Mounting Stud Broke

Vinoy Thomas said:

Hi everyone,

One of my rear studs on my GRUBEE GT5 motor broke of while I was riding. Half of the stud had broken off and the rest is still inside lodged in the motor.

Hopefully someone could help me out as to how I can replace this screw or if there is an alternate way of mounting the engine

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Must have answered 2 or 3 of these broken off stud posts recently
http://motorbicycling.com/showthread.php?t=42438

good info in that thread

not mentioned was in case there is no way to get it out (loctite or whatever), I've had good luck in drilling a bit larger to get it all out then putting a helicoil in to preserve the 6x1.0 standard

Vinoy Thomas said:

My only option is to drill the remaining screw out and clean the hole. I`m not familiar with all the bolt sizes and standards, so what should I do to re-thread the hole.

For the heli-coil method, what tools are required and how expensive are the inserts.

Also, if my local hardware shop does not sell thread inserts, what are other methods of re-threading the hole? Will I be able to buy a larger bolt?

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Huh? Did you read the link?
Your first option is to remove the broken off 6 mm 1.0 stud.
You will not need to rethread or use inserts.
It really ain't that difficult.
I do it all the time.

Did you use loctite on the stud?

it is but you cant drill it much larger or you risk losing the case strength

Vinoy Thomas said:

I will have to see if my local hardware shop has the easy out

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drilling larger is your LAST option, everyone should have a set of ez-outs laying around, when you need them, you really need them

Vinoy Thomas said:

Hey MotorBicycleRacing,

I read the link but I was just asking whether I would be able to re thread the hole with another bolt maybe of bigger size.

I will have to see if my local hardware shop has the easy out, but just for now with the tools I have drilling out the hole screw, and re threading the hole would be easier for me, would that be a possibility?

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You may not even need an EZ out if you didn't use loctite.
Unscrew the unbroken stud to see how tight it is.
You are going to replace all your studs with better quality, right?

First very accurately center punch the broken off stud.

Then drill an 1/8" pilot hole making sure that it goes down the center of the stud.

Then try a slightly larger bit and reverse the drill, sometimes the stud will come out.

Then if you have a dremel you can cut a slot to remove with a flat screwdriver.
If that doesn't work you already have a centered pilot hole to enlarge a bit to
use with an EZ out.

The square EZ outs work the best especially in the small sizes.

Turn the EZ out very carefully and don't jerk or force it because if
you break it off you are really screwed because they are very hard.