What do you think is the motor used in most racing applications?

[GD66]

BSA Gold Star must have been used at some stage in every discipline...

[80-85 husky]

The Early RM 125 a-b and c' Motors were very popular in sliders and go karts for a while.

it was interesting as Suzuki base all their parts on frame number sequences.

So all these guys with early RM motors in sliders etc would go into a Suzuki dealer and go "i need a 1st o/s for an 80 rm 125"

"or was it a 81?? ...could be a 79?"

Whats the frame no??

3 piston kits later... the right one would turn up at great expense to the poor bugger

[Tim754]

To quote Firko " It's a horses for courses thing but to me the mark of a good engine is one that can be adapted to perform any number of differing tasks with reliability and ease of maintenance"." versatility, and that's what I think makes a great engine " regarding the DT250 Yamaha, That is exactly my reasoning's for selecting the Triumph Unit (and pre unit) 650 and the Honda  K/F series CB750 Fours.

Is your selection versatile ? ie. Motocross/scrambles, enduro, trials ,trail rides, road racing, speedway ,long track ,short circuit, AMA flat track, ice speedway , rallying, hill climbs, drag racing etc etc
Reliable ? or does it need a fleet of factory technicians to rebuild it after ...every...outing.
Can you preform the basic maintenance it needs ?

 Maybe add these items to your thought trains.
Could you race bog stock as you received it from the shop or did you have waste lots of time and money to try to make it work for you?
How was the power delivery and the handling ? ( to be fair think relative to the era ) . Cheers Tim754