416, 426 or 440

[mach5racing4]

I was just wondering from people with those bores how reliable are their quads, I want to bore mine out but I dont want to have to worry about it overheating, or blowing gaskets. I want more power for trails and mx tracks. I have intake full exhaust, jet kit stage 2 cam, I dont want to buy a new carb if I dont have to. any info would help thanks alot guys!!

[400exrider99]

i havnt bored my 400ex but i have herd that the 440 is much harder to start than a 400

[mach5racing4]

harder for the starter? anyone have frequent overheating problems and which size is best?, thanks

[BlasterEaten250]

my brother had 87 octane in one time because it was all we had on his 416. after a while the headpipe was red hot. a 416 is reliable, just make sure you use 93 octane;)

I have a 416, overheating more depends on what comp ratio u run. if I am dirving in snow or doing lots of dounts in sand, I over heat easily due to the lack of wind with loads of work on the engine.

with a 11:1 comp ratio u can run on pump gas, just pick up some air scoops.

a 416 vs 426 vs 440 any one can be faster than the other, depends on your riding type.

if you like to rev the pisser out of your motor, then u will love the 416, makes loads of power up in the high rpms.

426 I havent ridden one yet, but I sopose it to have a little more bottom end or torque than the 416.

the 440 as I understand it is better for ppl who ride in low rpm ranges, engine reves slower than the others, but has more torque allowing u to change the sprockets around to use this toruqe.

I have the 416 with 10.8:1 je piston with cosmic thin gaskets, thing made good power. But I will be swaping to a 426 sometime this season I am shure, just to try it out.

[mach5racing4]

thanks, that pretty much answers my question, i do alot of snow riding donuts ice racing etc... i just want to make sure i dont overheat it all the time, i wish you could make the 400ex liquid cooled but o'well. i think i want more tourqe as aposed to high end power.

Originally posted by mach5racing4
thanks, that pretty much answers my question, i do alot of snow riding donuts ice racing etc... i just want to make sure i dont overheat it all the time, i wish you could make the 400ex liquid cooled but o'well. i think i want more tourqe as aposed to high end power.

then for u I would definetly say the 440. pick up some air scoops and u should be set. You will want to have hd head studs put in, it is cheep insurance. also U may want to look into the 10.8:1 comp ratio with thin gaskets. the thin gaskets have less chance of blowing out or somthin I guess....

call up c&d, they are more than helpfull there.

[400-416EX]

I have a 416 and the thing screws, I have a few friends that have 440's and they are always working on there bikes. The 416 is very reliable and I dont have to work on it all that much. :cool:

[stc416rider]

do a search u can find a lot of topics on this