Engine Case: Motor Mount Stud Depth - Filing Down The Case.

[yuckfoo]

How do I determine how much material I can safely remove from my case? I'm putting a shift kit on a Mongoose Dolomite and I need to remove material from the exhaust side mounting area. How many threads deep do I need to keep so that my studs remain secure?

 

[Wrench]

How do I determine how much material I can safely remove from my case? I'm putting a shift kit on a Mongoose Dolomite and I need to remove material from the exhaust side mounting area. How many threads deep do I need to keep so that my studs remain secure?

Not sure exactly what area your talking about that ya want to shave off the case?
I think you can remove 1/8" of material maybe 3/16" If ya got enough meat IDK
I'm basing this est. on a typical bolt hole thread depth.

Threads usually are 5/8" deep. and the hole is usually deeper than the threads by 1/8" to 3/16"
If the hole is deeper than the threads . You can tap more threads with a Blind Hole Tap

Also if ya got enough meat in the bolt hole depth you can very carefully drill the bolt hole deeper to tap more threads
Do not destroy the existing threads and only drill the hole deeper if ya need the extra depth
If ya use the bit for the tap you should be able to drill the hole deeper without destroying the threads.


To answer you question - Bolt Hole Threads are usually 5/8" but it will still be OK with 1/2" of threads

You should measure the thread depth and the hole depth so ya know what your dealing with.

 

[yuckfoo]

Not sure exactly what area your talking about that ya want to shave off the case?
I think you can remove 1/8" of material maybe 3/16" If ya got enough meat IDK
I'm basing this est. on a typical bolt hole thread depth.

Threads usually are 5/8" deep. and the hole is usually deeper than the threads by 1/8" to 3/16"
If the hole is deeper than the threads . You can tap more threads with a Blind Hole Tap

Also if ya got enough meat in the bolt hole depth you can very carefully drill the bolt hole deeper to tap more threads
Do not destroy the existing threads and only drill the hole deeper if ya need the extra depth
If ya use the bit for the tap you should be able to drill the hole deeper without destroying the threads.


To answer you question - Bolt Hole Threads are usually 5/8" but it will still be OK with 1/2" of threads

You should measure the thread depth and the hole depth so ya know what your dealing with.

I don't have enough room to get a plate between the engine and the bike tube. Now I'm running into clearance problems with shift kit's 17 tooth gear. This build gets more and more complicated with each passing day. I'm getting close to admitting defeat. I was thinking of abandoning the shift kit, but then I need a solution for rear brakes as I'd have to remove the rear disk brakes to fit the drive side rear sprocket.

 

[Wrench]

IDK how to mount a shift kit on your bike. I just had some info about thread depth for ya.

Another member should chime in shortly and help ya with this shift kit clearance issue. Hang in there baby