Totally ruined right rear mounting hole... now what?

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noobtard

noobtard

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So, I had a rear stud snap off below flush... My mom's boyfriend decided to drill it out for me..(grr)
there were still chunks of the old stud down inside the hole..

I finally got a couple taps today... ground the hole out to 13/64 and started tapping to 1/4" x 20.. which went fine.. I figured I'd try the 2nd Tap through one more time(it looked sharper...)

and snap.... now I had a TAP stuck way down in the hole...

had no way of trying to get it out... drill bits VS Tap = useless... so.. now what?

Any ideas? I'm thinking: Doomed..
( maybe a Helicoil if I can ever get the buried tap out?..would have to be a pretty big helicoil... down to 1/4" ish...)


so, what have we learned here?
Try an "Easy Out" first!....(when studs break...)
if you break a tap off.... uh,.. Don't try "drilling" it out....(try a "finger" tool... don't try chiseling it out....)
holes above the stock studs = badddddd.
 

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Cabinfever1977

Cabinfever1977

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find out what or if anything is in the engine next to the holes,if it is just solid metal and not a engine part,then you could drill and tap new holes next to the old ones. then you could just fill in the old ones. maybe a diagram of the engine block or somebody else might know. if you do make holes next to the old ones you will have to modify your mount.
somebody on this forum said that a diamond bit shaped like a ball on the end will drill out almost anymetal out of a hole like that.


your other option is another block($20+sh) or another engine($75+sh).
 
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spad4me

spad4me

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I have had some one try to steal my happytime engine.

I removed the the broken studs with a dremel .
First by grinding a slot into the broken bolt piece, slot as deep as needed use a small bladed screw driver to unscrew the
broken piece ...
Then on another broken piece which would not come out. By using a conical DIAMOND rasp to eat the steel use 2 or 3 with water or oil to keep the DIAMOND cutting . then re tap.
 
noobtard

noobtard

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as I think you can see, there isn't much left to re-tap these days...:-||
can't sleep because I'm too busy thinking about the stoopid thing..

so, how about attempting to dremel out all the steel/junk*with a diamond tip..(we're talking much bigger hole..) and then getting someone to Tig the hole shut? and then re-tap though that...(sounds hard..)
 
noobtard

noobtard

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Bikeguy Joe said:
Just re-drill right above the old mounting holes.
Click to expand...
That crossed my mind but.. with the stock mount that slides on the studs?... and notice how close that left thread is to "nothing-ness" on the other side? like 1.5mm... of metal...
 
Creative Engineering

Creative Engineering

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Noob,

You shouldn't have any problem drilling & tapping new holes in the case.

Unfortunately you are limited as to where you can drill them.

There are 2 case fasteners that run right through this area of the case, (photo below).

You could drill and tap below the original holes, and get about 3/8" of threads before hitting the case bolt.

Even though you will have to make an adapter plate, I think your best bet is to drill & tap for 5/16-18 beside each original hole as shown in the photo. You will be able to get 3/4" of threads.

The tap drill for a 5/16-18 is a letter "F" drill, (.257"). Yes; drills come in letter sizes A-Z. Many stores will have the tap & tap drill packaged together. I'm certain Vermont has combo packages.

Jim
 

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noobtard

noobtard

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^^
Ahahahah. hah.. ha... *cry*
(and I was wondering why those holes were so hard to drill out, and why the tap refused to start...)

Sigh, Thank You for your time and info CE, wish I would have went with your idea first.

LEARN from my stoopid mistakes People!..
(one might think at this point I'd be considering a new motor, sadly, I'm not that S-mart... Swiss-Cheese engine shall ride again!!...)

p.s. no bolts to go through on that new left hole at least...
 

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noobtard

noobtard

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well, I have my mom's boyfriend "Bob".. drilling the poopies out of my motor atm.. scares me... but, he was a machinist for 15 years... so I guess it's his turn...

Well, even he gave up on trying to get the tap out of that mounting hole...

*edit* after Dremeling for about an hour he finally got the tap out.. I now have a huge drilled hole where the stock mount was gonna end up with a 1/2" 20 bolt in it..
 
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Venice Motor Bikes

Venice Motor Bikes

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Mar 20, 2008
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Another thought, is to drill & tap new holes just to the right of the original ones... That would also give you a little extra tire clearance. (you would also have to offset the front mount too, so the engine is straight.) You can do that with a flat plate & "U" bolt.
 
noobtard

noobtard

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VENICE BOY said:
Another thought, is to drill & tap new holes just to the right of the original ones... That would also give you a little extra tire clearance. (you would also have to offset the front mount too, so the engine is straight.) You can do that with a flat plate & "U" bolt.
Click to expand...
You'd most likely have issues with the rear sprocket too...
 
Nashville Kat

Nashville Kat

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Apr 20, 2009
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Have you seen that Alumalloy stuff on TV? You heat it to 700 degress and it melts and forms-

If you can get the old stud out with an easyout, and the thread is damaged you can fill it with alumalloy and redrill and retap- if you have that stuff-

Or maybe just allumalloy or braze around a new stud in the larger hole?
 
noobtard

noobtard

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yes, I've seen the "Durafix" aluminum stuff.. if "Bob's" fix works I won't need anything like that..

I doubt that stuff would penetrate a hole too well either..

haven't tried it.. looks rather gimmicky' though..
 
F

fm2200

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Joe, do you recommend replacing the original mounting studs with better quality grade studs to prevent this type of thing from happening. Or is it just an over torquing the studs that create this problem?
 
Bikeguy Joe

Bikeguy Joe

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I would replace the studs with bolts, or all-thread. I have run a few with the stock studs, but I take them out, and loctite them back in with just a few ft./lbs. of torque.
 
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