Ive been finding some with the number 51671,are these ones fixed?

 

What's wrong with his hips

 

Yup, they're the wave 4 ones, packed with Battle Core Optimus, and manufactured this year as indicated by the 5 at the start of the number. The duff ones were manufactured 2014, have a number starting with a 4 and appeared in Wave 2.

(first digit is a year. Next 3 are a day. last is supposedly a working shift. So a 51671 toy was ,manufactured on 2015 day 167 which is 16th June, shift 1)

The first version in Wave 2 has hips that cause the legs not to sit in the correct position standing straight in robot or combined mode. The same problem affects the Red Optimus Prime, who doesn't have a fixed western version. The problem was corrected with Unite Motormaster and this change has cascaded down into Battle Core Optimus, the second version of Motormaster (both in Wave 4 and presumably the reason for Motormaster's reissue), Grand Scourge and presumably all future uses of the toy

See

Combiner Wars Battle Core Optimus Prime Hip Ratchets Redesigned - Transformer World 2005 - TFW2005.COM

For pictures of how the toy is affected and

Combiner Wars Battle Core Optimus Prime Factory Installed Hip Fix - Transformers

for pictures of what they changed inside the toy and what you want to take out of a Battle Core Op to fix and original Motormaster or the red Optimus.

 

I never noticed this, wonder if it's worth changing it to new MM

 

In my opinion, YES, it makes the world of difference to the toy and it's balance in combined mode.

The toy itself has a code number on it youcan check which batch it's from, as above. Look on the inside on his lower right leg

 

No it is not worth it. Easier to do the DIY mod fix. Unscrew the screws for the hips (be careful of the spring inside), flip the bottom ratchet/cog in there, add some Pledge floor polish if you want and reassemble.

 

I don't even notice mine slouching since I never pose them

 

Flipping the cog round means they'll be a flat surface opposing the teeth. Not sure how long that'd take combined weight for

 

Combiner Wars Hip Ratchet Upgrade – Nonnef Productions

Honestly just get the Nonnef ones. They're amazing! Got them for my Superion. Basically they fix the Menasor Ratchet alignment issue as well as doubling the Ratchet positions. If you are willing to do some DIY work these ratchets are worth their weight in gold.

 

Yep bought one and super happy with him,way better then the first one I had which I took back,just had to add some polish to his right arm above his elbow since it was super loose.