What did you use on the capstan to replace the perished rubber "grommet" from hell ?

Depending on what you used there could have an impact on the audio since it directly affects the tape going across the head.

Hi Docs, I used some thick wire insulation sleeve cut to length. I have read since that the thin fuel hose for remote control cars is an ideal candidate too. Maybe I'll see if I can get a better alternative as the insulation wire, whilst it works, is maybe a mm thinner in final diameter when fitted than what i have seen in pictures of a successfully replaced grommet using the fuel hose alternative. Having said that, it sounds OK for most dance/hip hop music but just a bit out on some of those sweeping strings on some chill-out type tracks ... that end up more wavering than sweeping ;-)

Hi, could be a problem with the motor itself; for instance bad electrolytic cap in the speed control circuit.

Thanks Seb ... I do have another donor tape deck assembly (including motor) ... so maybe I'll continue experimenting with each to see which is the best ... and there I was thinking I was finished ... I guess there is always a little tweak needed here and there with these ageing boxes ... it's a testament to their build quality that they even work at all after all these years stored unused in garages etc. :-)

You can go on tweaking these machines, that’s part of the fun.  The tape transport mechanisms in these things are never going to compete with high end home decks; however they are reasonable. Wow (or flutter) should not be an oblivious irritation, if it is there is a fault somewhere. Hope you get to the bottom of it. The GF-9191 is one of my favourites!

Just for your interest, here are some pictures during my boxes "Open Sharp Surgery" session ... taking my working cassette deck from my GF-9191E with its dodgy amp (one channel malfunctioning) into my new GF-9191X ... I spotted some interesting differences in the speaker design along the way ... along with already known differences in wavebands the boxes support, the different power connector/switch, and slightly different I/O ports on the rear of the units ...

Above = GF-9191X on Left and GF-9191E on Right

Above = GF-9191X Speaker Design (all looks quite modern)

Above = GF-9191E Speaker Design (Old Skool ;-)

Above = GF-9191E Speaker Design Close Up

Above = Half way through re-whitening speakers (which one have I done? ;-)

Above = Off white speaker before treatment

Above = Speaker all white again after surgery :-)

See my original post pic for the final outcome - I am very pleased with the results.

Very nice job on the speaker

I like the idea of using radio control car fuel hose for the capstan sleeve. Thanks for that.  Also very interesting to see the different speaker desighns. All the best with your restoration, be very interested in the cure for your wow problem; as I say don't rule out the motor, after 30 plus years they can become problematic.