Good motor for young, total beginner?

[VintageRacer]

I've bought my son a Mad Monkey kit for his 9th birthday and am wondering what is likely to be the best motor for him to start racing.
I realise a slower motor is likely to be quicker round the track to start with, but how slow?
I was originallly going to stick with the supplied 23 turn brushed but I have a 17.5 brushless that I was intending to put in my Optima. I am now thinking this might be better as a atarting motor in the Mad Monkey.

Will he be too slow with either of these and should I be considering a 13.5 or even a 10.5 ?

Thanks.

[Martijn]

I still run brushed,
I run a Trinity CO27 (27turn)

I love to speed of te motor, It's pretty quick for a 27T...

[Mouton]

Why not let him try it out with the brushed motor before you start looking for a replacement? 17.5 brushless roughly translates to 27T brushed, so if the stock motor is too quick, try your other one before you get a new motor. That way you can compare two different winds, giving you a good idea of how "hot" any possible replacement should be.

If you already have your spending trousers on and an itch to buy something right now, get a spare battery.

[VintageRacer]

I've already got the brushless set-up, it just means I'll have brushed in my Optima, so no spending needed for the 17.5t, but I was wondering if it would be competitive for a beginner. I would prefer brushless because of the ease of maintenance, also the brushless ESC already has lipo cut-off so no need for the Novak smart-stop, one less thing to wire in and find space for.