Truss rod tool for Yamaha FG 700s

[Corwin1968]

I have, as best as I can tell, a 2016 Yamaha FG 700s that I bought used in 2019. A few months ago, I realized the strings were totally dead and asked the owner of a local guitar shop what strings he would recommend, which were Martin 12's.

The previous owner must have had lighter gauge strings on it, because the neck is very visibly bowed. I don't know the correct "forward/back" terminology, but it's obvious there is more sting tension on the neck than the truss rod was adjusted for.

My online searches indicate a 5mm allen is the correct tool, but my 5mm allen won't fit into the truss rod and a 4.5 fits but is too small to engage enough to turn.

Do some Yamahas have a truss rod nut that is between 4.5mm and 5mm?

[Fathand]

Originally Posted by Corwin1968

I have, as best as I can tell, a 2016 Yamaha FG 700s that I bought used in 2019. A few months ago, I realized the strings were totally dead and asked the owner of a local guitar shop what strings he would recommend, which were Martin 12's.

The previous owner must have had lighter gauge strings on it, because the neck is very visibly bowed. I don't know the correct "forward/back" terminology, but it's obvious there is more sting tension on the neck than the truss rod was adjusted for.

My online searches indicate a 5mm allen is the correct tool, but my 5mm allen won't fit into the truss rod and a 4.5 fits but is too small to engage enough to turn.

Do some Yamahas have a truss rod nut that is between 4.5mm and 5mm?

A 3/16" allen key = 4.76 mm, did you try one of those?

[YamahaGuy]

There are two different truss rod wrench sizes for my acoustic Yamaha guitars. I'm sorry I couldn't tell you what sizes they are, but some are black and some are stainless?

[Corwin1968]

Originally Posted by Fathand

A 3/16" allen key = 4.76 mm, did you try one of those?

Just tried, and it's too big.

I tried the 4.5 again and it does fit, but I think it moves too easily to be actually adjusting the truss rod. I base this on the feel of adjusting a brand new Taylor and a brand new PRS electric. The truss rods on those had a little resistance.

[YamahaGuy]

Two way truss rods will feel like the turning of the truss rod nut isn't doing anything when it's between bow and backbow. Hopefully it's not backed entirely off the threads...if it's a one way.

[Fathand]

Originally Posted by Corwin1968

Just tried, and it's too big.

I tried the 4.5 again and it does fit, but I think it moves too easily to be actually adjusting the truss rod. I base this on the feel of adjusting a brand new Taylor and a brand new PRS electric. The truss rods on those had a little resistance.

I hope your truss rod isn't broken or stripped.

[phavriluk]

If OP's truss rod adjustment offers little to no resistance. can the wrench be turned - - - how much in either direction - - - and eventually encounter resistance, or never?

Dead certain the wrench is engaging the truss rod and actually turning something?

Is it possible that the truss rod is loosely made and it takes a lot of turning to get past the dead band?

That instrument is pretty far down Yamaha's food chain, is it possible that the truss rod behavior is common in that price point Yamahas?

Is there a Yamaha guitar forum to bring this question to?

[Retired1]

are you sure you're turning it the right way - clockwise looking from strap peg to tuners ? If so keep on turning - they are often easy to turn at first - tighten it a quarter turn at a time, while checking the relief - good luck.