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Coil Mount Studs

PostPosted: Wed Aug 10, 2016 3:01 pm
by Zaemo
Can anyone tell me... does the SHORT hex stud go in the top or bottom bracket? When it's in the top position, it fits better despite the box not being straight up and down. When it's in the bottom position, the coil cover hits the fender at the bottom.

I've seen them advertised as 4 1/8" and 4 3/8". My longer one is more like 4 1/4".


Z

Re: Coil Mount Studs

PostPosted: Wed Aug 10, 2016 5:23 pm
by thefrenchowl
Hi,

I have always assumed short = K, long = KH/Sportster...

Sort of confirmed by my KK battery quite often grounding on the tool box and smoking...

Patrick

Re: Coil Mount Studs

PostPosted: Wed Aug 10, 2016 5:34 pm
by Zaemo
Funny you say that. I've got two of each and was going to try two long ones. The kits have one of each. ? I'm waiting on my coil bracket for final fitment.
Z

Re: Coil Mount Studs

PostPosted: Wed Aug 10, 2016 10:31 pm
by JerrryR
Hi Guys,
Sorry, with out looking at my bike I can't remember off the top of my head short on the top or bottom. I can tell you that the Ks use the narrower studs with 5/16 coarse thread through 54. 55 & 56 Ks and the XLs used the fatter studs with 3/8th fine thread studs. All of them use a short and long stud. (This is to the best of my knowledge today).
Jerry

Re: Coil Mount Studs

PostPosted: Wed Aug 10, 2016 10:46 pm
by hennesse
Zaemo wrote:Can anyone tell me... does the SHORT hex stud go in the top or bottom bracket? When it's in the top position, it fits better despite the box not being straight up and down. When it's in the bottom position, the coil cover hits the fender at the bottom.
I've seen them advertised as 4 1/8" and 4 3/8". My longer one is more like 4 1/4".
Z


Zaemo,
What bike are you working on - I can't remember. I measured what I think are original 64612-55 and 64611-55 and they measure 3-11/16 and 3-7/8, not including the threaded area. These were used from ~1955 up till 1967 at least.

I have what I think are original 64612-52 and 64611-52 (1952-~1954), but they're mounted on my bike, so I'd have to take them off to measure them. They should be the same except for 5/16 NC? threads instead of 3/8 NF? threads, but who knows, they could have changed the thickness of the frame mounts.

Are you working with originals or reproductions?
Dave

Re: Coil Mount Studs

PostPosted: Thu Aug 11, 2016 12:16 am
by Yard Dog
Z,

Just checked my 57, short on top . Still mounted on bike so measurement approx. Looks a hair shorter than Dave's but I can't verify mine are original.

Is your 57 a low VIN ? It appears your rear cylinder has the casting date on the primary side, not the cam side like later 57s and on. Is your front cyl similar ?

Jack

Re: Coil Mount Studs

PostPosted: Thu Aug 11, 2016 1:57 am
by Zaemo
Thank you for chiming in, fellows.

Dave - 57 XL
To confuse matters, I asked the eBay seller who has a NOS 64611-55 to measure the stud advertised as a LOWER. It's 4 1/8" and corresponds to the lower stud if you believe the drawing. So that tells me Longer on top and Shorter on bottom.

I do not know if mine are orig or not. One pair came with my bike and bought another pair at a meet. Both sets were painted but are park now. Yes on the Fine Thread as well.

Jack, that's very interesting about the casting placement. Mine are a matching pair. Here's another picture. VIN# is 1623.

I'll try the short one on bottom again tomorrow.

Re: Coil Mount Studs

PostPosted: Sat Aug 13, 2016 2:56 pm
by Zaemo
I have the short stud on the lower for now. The tool box doesn't line up with the coil cover half with the spacer between the battery bracket and box foot so it's on top for now.

I also need smaller washers for the tank mount bolts. These 57's seem to leave no room between the rear rocker box and the tank mount and tank mount frame boss.

Here's a sneak peek at my progress. I still need a timer and some foot peg supports if anyone has extra.

Z