ZZR1200 Alternator Upgrade

[gbyoung2]

Was fooking around with the bad ZZR alternator a fella sent me a number of years ago, the parts fiche, and the instructions that Brock Delp wrote a few years ago. The fiche calls for 8x65mm long mounting bolts. Brock's instructions call for those same bolts. Funny thing, the thickness of the three (3) mounting bosses on the ZZR alternator is exactly 65mm. The three (3) bolts the fella sent me with the alternator are about 80mm long..... long enough to pass through the alternator and have good thread left to secure it to the engine case.

What the hell am I missing??

 

[bajasam]

15mm of thread are'nt counted in length

 

[gbyoung2]

15mm of thread are'nt counted in length

Interesting, never noticed.

Guess that means that a fully threaded bolt has a length of "0"

 

[bajasam]

different fasteners are measured different ways for different usages, a shanked bolt for shear loading generally doesn't count threads in length as there is no strength in the threaded portion.

 

[gbyoung2]

different fasteners are measured different ways for different usages, a shanked bolt for shear loading generally doesn't count threads in length as there is no strength in the threaded portion.

Excellent. Never had an issue in all these years fooling with bikes and their respective fiches, but that info will sure keep me from picking up a piece of hardware based solely what I'm seeing in those fiches. Fully threaded, not so much, but a partially threaded bolt - be aware.

Old dog, new tricks.

Thank you.

 

[bobct]

I always measured full length including the thread length for socket cap screw ordering.
You may be right but....see bolt diagram in this link.

https://www.boltdepot.com/Product-Details.aspx?product=6570

Shoulder bolts are measured and sold by the shoulder length only as shown in link below
https://www.boltdepot.com/Product-Details.aspx?product=14244

Are the bolts you received with the alternator regular bolts are does the unthreaded portion fit snugly in the alternator (larger diameter than the threaded portion)?

I still have a ZZR alternator on a shelf that I have to install so this information is useful to me too.

 

[gbyoung2]

I always measured full length including the thread length for socket cap screw ordering.
You may be right but....see bolt diagram in this link.

https://www.boltdepot.com/Product-Details.aspx?product=6570

Shoulder bolts are measured and sold by the shoulder length only as shown in link below
https://www.boltdepot.com/Product-Details.aspx?product=14244

Are the bolts you received with the alternator regular bolts are does the unthreaded portion fit snugly in the alternator (larger diameter than the threaded portion)?

I still have a ZZR alternator on a shelf that I have to install so this information is useful to me too.

The bolts that came with the bum alternator are the ones shown in the ZZR fiche. Can't say that they're "snug," but the appropriate size for the application. The thickness of the alternator bosses where the bolts pass through are 65mm, the length specified in the bolt's definition in the fiche, and that's what was confusing to me. The threaded portion that engages the engine case extends another 15mm or so more.

If you get the bolts shown in the ZZR fiche, you'll be good.

The way Bolt Depot illustrates the length of a socket head cap screw is the way I was expecting the dimensions in the Kaw fiche to show...... and that's what was throwing me off. I wonder if Honda does the same? I've only ordered fully threaded screws from them, not partially threaded bolts. No Hondas in the shop right now, so no reason to order anything. 

 

[MAN OF BLUES]

the common cap screws all switch over to "partially threaded" types right around that 2-1/2" to 3" long mark, depending on diameter. It's a strength thing, the solid shank is generically industry standard, as the threads are "rolled" into the shank, so it reduces the chance for a fracture point just below the head, where the bolt is the weakest when it's fully threaded.