Well, I had my first try with the 740Kv moter, and probably should have gone for the 1100Kv instead
I used the original yokomo YR-4 tourer and removed the entire front transmission and the center shaft with its spur and pulley. tapped the shaft of the moter through to the other side and mounted a 5mm bore pulley on the shaft. A shorter belt over the pulley to the diff was all it needed to finish the conversion. But I took some extra time and rearranged the electronics and switched to saddle packs. Al that to bring the weight more centered and further to he back: all possible now the fwd belt and spur were out of the way.
Unfortunately I only ever found one of those pulleys I now use as 'pinion' and it is clear it needs more teeth. The acceleration to top speed is immediate but it goes noticeably slower at top speed than a 540 mabuchi powered TT-01. It also comes to a stop way too quick instead of rolling out.
(No, the belt tension is fine, thrust me on that)
I guess I could try finding another pulley before upping the moter: anybody with ideas? It should be M3 module and a 5mm bore.
I do still have other ideas for use of the 740 KV moter, so It's not hat bad if I can't get the YR4 to work as it should. (The car was running great before, and 4WD, so I don't mind getting it back to its 'normal' state)