Aiwa TPR 940 replacement idler tyre/tire help please.

[Demonfinder]

I currently have a guy servicing and repairing a Aiwa TPR 940 for me ..he`s already done two excellent jobs for me and has run into a bit of a problem.
He`s de-gunked the old melted rubber belts but the idler tyre has gone to mush too.
I thought I`d found a replacement on ebay in Germany but my repairer contacted the seller who now says the advertised part may be from a Sharp.
If any one knows either the measuresments for a replacement/substitute I`d be grateful.
Or if you know the same cassette mechanism was used in other model numbers which might help me track down a replacement online.
Another problem he`s found after repalacing the belts is :
"Some problem where the auto stop engages immediately now. On Play, FF and Rew.
If Pause is engaged, auto stop is inhibited. (I’ve accounted for the missing idler, so it’s nothing to do with that.)

If anyone hads ideas as to what the cause of this auto stop problem might be please get in touch.
Many thanks in advance.

 

[Tinman]

You probably know this but most auto stop mechanisms are mechanical.
As long as the reels are turning, the function continues.
Once the reels stop, like at the beginning or end of a tape, the auto stop kicks in.
What do you mean by "I've accounted for the missing idler"?

 

[Demonfinder]

Thanks for that @Tinman ...maybe the repair guy the repair guy was either unaware the autostop function continues as you said or just temporarily forgot.
His comment about having accounted for the missing idler suggests to me that he has discounted the idler having a direct impact on the autostop problem.
My own technical knowledge is very limited (along with my fixing up abilities !) so I get most of my hifi/audio stuff fixed up professionally.
He`s bought back to life both my 950 and 968 so far and currently has the 940 and an old Nad record deck for a service.

 

[Demonfinder]

My repair guy got back to me yesterday to say he`s found the prob with the autostop ( didn`t mention wether it was due to your comment though @Tinman :0) )
He`s now found the following :
I found the issue with the auto stop.
Now when it actually runs on (not working with tape due to no idler wheel), there’s a very obvious issue with tape playback:
Motor noise injected into playback amp at very high level. (Same with mains power or 9V DC power.)
No point getting the idler before that has been sorted.

So it`s one stop forward,one step back at the moment.
I`m sure he`ll find the noise solution but I`m still on the lookout for help with the Idler tire details or spare .