Motor and Battery for Pb mini mustang

[Japon1971]

hi
Ive just received my pb mini mustang complete with original futuba transmitter,reiever and servo.
It has also been fitted with a parma yokomo motor which appears to be period correct.
I gave it a quick run using a 3000mah 7.2v battery pack and although everything works fine the car itself was quite slow.
I have checked the brushes on the motor which seem fine.
Im wondering wether I need to use a more powerful battery pack or is it more likely to be the motor or electrics due to their age.
I had intended to try and buy a Demon power motor for this car if I can find good one.
Any advice on why the car could be running slow or where I can get a demon motor would be much appreciated.
Thanks Jason.

[Dadio]

There could be a lot of reasons ,
What wind is the motor ? if its a 27 turn motor it could be slow .
what pinion gear is fitted (how many teeth) ? if its a very low tooth pinion it could be slow
what spur gear is fitted(how many teeth ) ? if its a very high tooth spur gear it could be slow .
Then it could be something binding , do the diffs run smoothly if you spin one wheel ?
does it have the two speed transmission , is it getting into second gear ?

[Japon1971]

Hi
Thanks for your reply.
I have checked the car and the pinion gear has 14 teeth and the spur gear has 58 teeth.
There are no markings on the motor to determine the spec but its black with a white sticker and parma yokomo written in green.
I will try and attach a photo.
I have checked the diffs and it all seems to rum smoothly and the car is also a single speed 4wd version.
Thanks Jason
https://i.ebayimg.com/images/g/fjkAAOSwL5ZlNj7N/s-l1600.jpg

[Dadio]

That's low geared , as comparison that's roughly the same gear ratio as my two speed has for first gear , I'd try a 17 tooth pinion but check your motor temperature after 4-5 min to make sure it's not too hot , you need to remember these old motors were designed for roughly 5 min runs as the old 1400 mah batteries only lasted that long , your 3000mah battery will last more than twice that !

[Japon1971]

Thanks I will order the pinion and see how the car runs.
I was part of a club in the 80’s and did have and race a mini mustang using demon motors.
I remember it being pretty quick.
I assume if I fitted a modern tamiya tuned brushed motor it would run for longer and not get too hot.
My sons tamiya lunchbox runs for ages on one battery and it’s fairly quick.

[Dadio]

I'd try the new pinion first and see where you are , mind you the Parma Yokomo is a nice vintage motor and a new Tamiya sport tuned is kind of expendable so not a bad idea .