Go with a fully race ported 240 big bore with a long rod and a stroker, Keihin 33mm PWK riffled and bored, cases matched, degree key, Power Pros or LRD exhaust, head milled as far as you can safely go and rechamber the squish, run race fuel, larger rear tires, and taller gearing. It all falls down to achieving a good amount of hp and torque so that you can run taller gearing and larger rear tire size thus resulting in more power and increased top speed. It can be done but speed and power cost money. Talk to this guy www.hollywooddirtproductions.com If you really want to boost your hp even after youve done the above mentioned mods you can switch to running on alky.

 

the two stroke should have no problem staying with the 300, but i dont know if it would keep up with the 400, stock.
actually the power diff is around 1.8 tymes

 

im pretty sure this was asked recently

 

Why do you think they race dirt bikes 125 two strokes against 250 four strokes, or 250 two strokes against 450 four strokes? It because a two stroke puts out twice as much HP, so to keep it all fair, four strokes can have double the cc's, and as for the zilla vs an R1, well thats just a totally different thing, an r1 is a four cylinder and its like saying a raptor will beat an r6 because the r6 is only 600 ccs come on, I mean even a kawaski ninja 250 does 125 (according the the speedo 130) so comparing street bikes to quads that wernt meant to hit over 100 is like comparing apples to oranges, but a zilla is a mean bike[img]i/expressions/face-icon-small-cool.gif[/img]

 

yea but whenever I see motocross races on tv I always see the the 4 stroke 450's beating the 2 stroke 250's and I knew it's more the rider than the machine and maybe when I don't see the races the 2 strokes win I don't know but windham on that 450 is doing mighty well this year. And if you what you are saying it doubls in power then shouldn't the 250 have more power because it be considered a 500 4 stroke by what you are going by and the 4 stroke is still a 450 so I will admit a 2 stroke 250 has more power than a 4 stroke 250 but it doesn't have twice as much power that it would make it equal to a 500.

 

Sometimes too much explosive power can cost you seconds in a race and you lose too much traction, compared to a smoother 4 stroke power delevery that has more of an advantage coming out of the turns, and the main difference to me is the fun factor which is 10 times more on the 2 stroke if you recreation ride and just want to release some stress as you roost up a storm and hold on for dear life!

 

every1 is bein way to serious lol...jus get a raptor an mod it up an blow every1 away hahaha

 

The actual number is something like 1.73. That means a blaster would be similar to a 350cc 4 stroke, namely the warrior. The warrior takes a stock blaster, however, so its very close. And yes, a 250r or the like should be able to run with a 440, hence the reason that 440cc was the class limit for 4 strokes for so long. (that makes sense now doesnt it...) That is why the 250's run with the 450's. It would take about 875cc of 4 stroke quad to equal the 51hp output of the zilla, which explains why stock ones still beat my raptor...

 

stock 250r's can't run with 440's and 450's

 

really? maybe you havent raced any decent riders then. they run with them. with a few minor mods or a small bore they will run with a piped raptor. a 310 will beat a piped raptor if its done right