What to expect from USACG parts, and the difference between Japanese and US made Jazzmasters.

This post isn’t really about guitar repair, but I think it answers some questions I had about discrepancies and problems I had with my neck and body, some of them went unnoticed for months. The short version of it is that their bodies aren’t identical to actual Fender Jazzmasters, even after doing the work that’s needed in order to fit Jazzmaster hardware to them. The necks (or at least mine) have a few problems too.

First, I’ll start with some measurements. I asked a friend to measure a few distances on his 65 Jazzmaster to help me understand what was wrong with mine. Here they are:

  • It’s 7-3/16″ (7″ and 3/16″) from the bottom of the neck (where you adjust the truss rod) to the imaginary line running between the centers of the thimble holes.
  • It’s 5-1/2″ (5″ and 1/2″) from the bottom of the neck to the center of the pole pieces of the bridge pickup.

Mine also measured 7-3/16″ from the bottom of the neck to the center line of the thimbles, but the second measurement was off – mine was a little shorter. That explains why an AVRI pickguard fit they way it did on mine:


When the pickguard sits on the guitar so it fits over the thimbles, it sticks back behind the bridge pickup by about 1/8″. Of course, trying to get it to fit over the pickup cavities prevents it from sitting right over the thimbles. I believe this is the big difference between Japanese and reissue/vintage Jazzmasters routes. I confirmed it with an Allparts guard (made in Japan for Japanese Jazzmasters) which fit perfectly over the guitar. A Pickguardian guard also fit perfectly over the guitar, so keep that in mind if you’re looking to buy a pickguard from them for your American Jazzmaster. However, I did make these comparisons in September 2013, so maybe things have changed on the Pickguardian front. By the way, I made a video comparing the two guards. I didn’t post it because it’s 80mb, but if anyone wants to see it, I’ll be happy to upload it.

My fix for this issue was to enlarge the bridge pickup cavity. I did it with sandpaper and a drill with a weird grinding bit. Now I would use a router like a normal person would.

The next issue with the body isn’t really an issue, but it’s annoying nonetheless. The thimble holes aren’t big enough, so they must be enlarged by the customer. This is kind of a pain in the ass because if you try to drill the holes to make them bigger, you’ll have to figure out how to align the center of the drill with the center of the existing holes. If you go the sandpaper route, it’ll take over an hour with 80 grit sandpaper to make them big enough.

Next on the list is the tailpiece cavity. It’s not long enough and the corners are radiused. This means that when you use the tremolo, the plate hits the back wall of the cavity and won’t fully release, so the guitar goes out of tune. The fix is to install the tailpiece, use the arm, see how it works, file or sand the back wall, repeat.

The next two issues are more annoying to me than the ones above, because they can’t be fixed (at least not easily) and they really make this guitar not look like a Jazzmaster.

First, the body is thicker than other Jazzmasters. I noticed that after receiving mine and then looking at some JMs at a local store. I took a caliper to my guitar and the body thickness measured 45.65mm. According to this thread and this one Fender’s Jazzmasters are somewhere between 39mm to 42mm, with older Jazzes being thicker. It doesn’t seem like much, but 5mm times the surface area of a Jazzmaster is quite a bit of material, and indeed my guitar is heavier than any other Jazzmaster I’ve ever picked up.

Then there’s the issue of the radius of the sides. I’m taking about the radius that is cut with a router once the shape of the body is formed. The sides on mine are barely rounded. I mean, they are, but it’s a very small radius. Actual Fenders have a bigger radius and don’t look so boxy. I think Stew-Mac sells the right router bit for rounding over the sides.

Like I said, these two issues are the worst for me. The others I was able to fix and are unnoticeable. The Japanese vs. American route – who cares? So the pickup was moved by 1/8″. I doubt it affects the sound much, and no one would have been able to tell that this is a Japanese route Jazz just by looking at it. These two issues though, the radius of the sides and thickness, I’m still annoyed by them.

On to the neck. The frets on mine weren’t pressed or hammered all the way in, as can be seen in these two images.



Pretty much all the frets looked like that and it really bugged me. They felt stable, but still weren’t properly seated. Since this guitar was my first ever project pretty much, and I’ve never done any fretwork, I sent the neck back so they can seat the frets properly. To be honest, for an almost $300 neck, they should have gotten it right the first time.

Then there’s the truss rod. With strings on, I couldn’t tighten the truss rod enough to get adequate relief out of it, not to mention getting it straight. I don’t know what caused that. Maybe the nut was running out of threads, or maybe the pocket where it sits isn’t deep enough. Cutting more threads onto it and adding a washer helped. Still not a perfect neck, but useable. I also I assume the neck isn’t reinforced (other than the truss rod). Almost every Fender neck I’ve seen had some amount of twist (treble side has more relief), and this one does too. I think adding some carbon rods under the fretboard could have helped that and kept the neck straight, but alas, it’s twist. For what it’s worth, though, the twist has gotten better, so maybe it’s a question of the wood settling.

Lastly, the headstock is very small (like a 50s Strat) and doesn’t look exactly like a Fender headstock. The biggest difference is that it has a little nib (look up a USACG headstock) which I sanded off. The difference in looks never bothered me that much; it might bother others.
I should say that theĀ  folks over at USA Custom Guitars were very nice and tried to be as helpful as possible. When I showed them the American pickguard doesn’t fit right, they sent me a pickguard from Pickguardian. When I showed them Pickguardian’s is the same as Allparts they sent me a new body (I returned the first). However, the new body had the same issues as the first, so I concluded they route them all like Japanese Jazzmasters. They said their CNC plans are made from a 62 or a 63 Jazzmaster, and maybe the outline is taken from a pre-CBS Jazzmaster, but not the routes. At this point I decided to keep the body and fix what I could myself. Like I said earlier, they also took the neck back and fixed the frets problem. So they really were very helpful with every concern that I brought up. However since I worked on that guitar for months, some concerns I felt uncomfortable voicing. For instance, it was over 6 months after I got the neck that I noticed that the truss rod isn’t working properly, and it took me even longer to notice the twist in the neck. Overall I have a fine guitar and I learned so much in the process of putting it together, but if it was all about just getting a nice Jazzmaster, then buying a used reissue would have been the best and easiest way to do it.

Edit: This is a big one. The neck pocket and neck have the tightest fit I’ve ever seen, and that’s pretty cool. I foolishly didn’t align the neck in the pocket with kite strings, and the alignment ended up being perfect. I mean, yeah, there was no room to move the neck in the pocket, so that makes sense.