ugh, fuck i went to school for all this shit
Z400/KFX400/DVX400 are all the same quad, same motor ect. tons of aftermarket support
same with the 400EX
all are pretty bullet proof.
everyone has there opinons, ill tell you what i have seen a alot of
400EX motors/head/vlave blown to hell but thats due to to high compression. people put a high comp. pistion in and slap a pipe on it call it good.
not
yamaha’s like to smoke the crank bearing turning your crank a nice blue
some year LTZ450’s the shock will break off due to a welding error.
the larger KFX700 is heavy and a pain in the balls to work on.
the KFX/Z400 seem to be pretty decent havent seen a common issue with them.
DVX400 plastics suck snap on snap off BS
watch out for FI quads if you mod them, the stock map is not that big needs to be taken to a shop.