How do Mini-4-Strokes Compare with Each Other?
By Jerry Matta



If you haven't ridden many mini 4-strokes you can't assume bigger is better.  It's not like comparing a 125 to a 250 where the technology is of the modern age.  All mini 4-stokes built today are based on 20-30 year old technology and the design is chosen by whatever is on the shelf and in decent supply at the time.  Also, you can't use dyno numbers from different dynos, they all measure differently. Why, I don't know. For instance I know that the BBR dyno measures a bit higher than the dyno we use down here, which isn't bad, but you can't say mine dynoed at 12hp up here and yours dynoed at 10 hp down there so your sucks; you just can't compare the numbers.  What dynos are best at is saying,"this is the stock curve and this is the modified curve and we did X amount better.".  Then there's torque, where the power is along the curve etc.  But that's a whole other story.

Here are the numbers from the same dyno:

Real life on the track:

I'm comparing these because people have misconceptions about all these bikes. Mainly because when I was selling my bike people email me and say they could get a CRF150 or TTR125 since their faster, when in fact my bike has 2hp more than a stock 150 and out pulls a fully modified TTR150 on uphills.  And it's impossible to argue with anybody, but for example if you look at the TTR125 exhaust port you'll know what I mean. If all the motors were built to the same specs flow wise, with ti valves etc. like a mini 450f  bigger would be better, but with these little bikes it doesn't work that way.  Until a company (probably Yamaha) comes out with full race mini four stroke we have to put up with all this.