race a blaster for motocross

[national425ex]

Alright, I usually race XC with my bored out 400ex. Here recently I have been wanting to do some motocross as well. My dad and I think that I just build the motor on my blaster and run in the 350 and under sport class. The blaster already has a 4" extended swingarm, +3+1 arms and works triple rate shocks. It also has 18" holeshots on the back with 19s on the front. It is pretty much already setup. It needs tp be rebuilt, so I would add a big bore and stroker crank on it. The problem is, I am 20 years old and by brother thinks I am to old to race the blaster. My dad and me kept bringing up that Joey Margaria races a blaster in the gncc sport class. My brother thinks joey is alot younger then me, but I thought he was right around 20. Maybe Im wrong. Im just wondering what everyone thinks about this idea.

[Tri-valleyracin]

just race the 400ex in both. for motocross your too old to race a blaster competively. unless ur small around 5'5". you could do ok on a blaster with a huge big bore and porting but thats goin to cost you the same as buying an other 400 or used 450.fix the top end and sell the blaster and buy an other 400 or 450 and have two bikes one for xc and one for mx. look up the rules for racing in ur area.

[national425ex]

already checked out the rules, THe only motocross track I was at are outlaw tracks and dont really have to many rules

[Tri-valleyracin]

ok then, you can race the blaster but it wont be near as fast as a 400 or 450 on the mx track. or if u have the skills put a yz250 motor in it and it will keep up or out run the 450s.