both starter bolts broke off in 62t case

Freakrider

Freakrider

X247
Location
Tampa Bay area
asking for options for a friend...I know that a cobalt drill pilot hole is the first step using an extention drill holder...who has real experience with this and has tips/advise for getting these bolts drilled out....thx
 
WAB

WAB

salty nuts
Location
coastal GA
If he's not afraid to mix case halves, get a cheap 6m6 (650cc) bottom half. I'm running mixed cases, 6m6 bottom & 61x top.
 
Matt_E

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
My cases had the bottom bolt broken off (before I bought it). Somebody drilled it out, and now I have to use bolt + nut, but it works.
However, I cannot change the starter without taking the engine out.
 
S

sflsurfrider

Matt_E said:
My cases had the bottom bolt broken off (before I bought it). Somebody drilled it out, and now I have to use bolt + nut, but it works.
However, I cannot change the starter without taking the engine out.
Click to expand...

i was going to suggest that as a worst case scenario.
 
feartheride

feartheride

feartheride
Location
St.Catharines,On.Canada
Jump On It said:
asking for options for a friend...I know that a cobalt drill pilot hole is the first step using an extention drill holder...who has real experience with this and has tips/advise for getting these bolts drilled out....thx
Click to expand...

If the bolts are broke I am assuming they are siezed in there. If that is the case extractor likely won't work and you will have to drill them out. you have to start as straight and on center as possible. Start with your center drill and then use a small drill and work your way up.Use of to big of a drill right away will tend to wash off center. You can try the easy out and a bit of heat Aluminum expands quickly. If it does not work keep drilling till you are close to one side of the threads or close to tap drill size if you are dead center. the rest of the bolt should collapse and allow you to turn or pick it out. Even if the hole is damaged you can helicoil or timesert.
I use Left hand drill bits at work alot but they are good when the bolt is not siezed because with the little bit of heat they cause the bolt comes loose and spins out while your drilling

Good Luck
 
S

sflsurfrider

...and dont forget to start the hole with a spring-loaded center punch :wavey:

center_punch1.jpg
 
Wave Chaser

Wave Chaser

Location
League City, TX
slow and careful like featherider says. i did 2 cases just like that last year and was able to save the threads and still use same size bolts and it has held up.

Just make sure that first small hole is as centered as possible the rest is downhill from there.
 
K

Kennay

Squarenose for the _____
Location
Myrtle Beach, SC
Left handed drill bits kick ass. If you have the pilot hole centered, on the last hole you drill out, you can pretty much always bank on the left hand thread coming through for ya. The main thing is, even if you mess up the threads, you want to ultimately be able to at least helicoil the hole as centered as possible with it's original center of origin. Like mentioned, it's all in getting that initial hole drilled as centered as possible...
 
ChuckBiscuits

ChuckBiscuits

My best advice is to drill it all the way out and use a nut and bolt to hold it on. I broke my top bolt off then broke the extractor trying to get it out. Once that happens you're in trouble because extractors are pretty much impossible to drill out.
 
W

waxhead

wannabe backflipper
Location
gold coast
I would centre punch it
The drill it out completely once you have done this its a simple helicoil

But make sure you take your time to do it right
 
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