Moving the power band higher...

[Screamin440]

Okay, I bought this quad used from Dreyer with the mods already installed. They don't know exactly what was installed. The salesman assumed it was a 440 with a stage 1 hot cam in it.

Here is my problem... this motor is EXTREMELY torquey down low but it doesn't really make power up top like I would like. What all can be done to make this thing wind out up top without sacrificing a ton of bottom end torque? I would like it to run like a Z440 if it all possible. How much will head porting help with the top end power? Will porting sacrifice a lot of my bottom end in order to get it to make power?

[srooney_12]

put in a stage 2 hotcam. it will give you more top end. get a rev limiter too

[cals400ex]

a stage 2 and a good high flowing complete exhaust system will be your best bet at first.

[DaleJrFan]

how many teeth does your front and rear sprocket have? mess around with the gearing first and that might save you a lot of money.

[Screamin440]

Stock up front and one down in the back.

[frosti108]

you say the salesman assumed what was in the engine... so you probly arent sure of the 440 and the hotcam... right?

1st thing i would do before ordering parts is open up the engine and see what your working with. id say theres a good chance its already ported and polished if its got a 440 and cam.
who knows what else is done...
open it up and take a look :)

[Screamin440]

Originally posted by frosti108
you say the salesman assumed what was in the engine... so you probly arent sure of the 440 and the hotcam... right?

1st thing i would do before ordering parts is open up the engine and see what your working with. id say theres a good chance its already ported and polished if its got a 440 and cam.
who knows what else is done...
open it up and take a look :)

Well, there's a guy I know who owns a 400EX stock bore with a stage 1 hot cam and basically the same mods and mine runs considerably better than his. While it may not be a 440 I do believe it is a big bore. Top end power is okay but the bottom end torque of this thing is just amazing. I can be doing about 5mph in 2nd, pin the throttle and not stall it. Then again if you take a 440 and put a stage 1 in it, it turns it into a tractor instead of a high end screamer.

[khen]

Originally posted by Screamin440
Well, there's a guy I know who owns a 400EX stock bore with a stage 1 hot cam and basically the same mods and mine runs considerably better than his. While it may not be a 440 I do believe it is a big bore. Top end power is okay but the bottom end torque of this thing is just amazing. I can be doing about 5mph in 2nd, pin the throttle and not stall it. Then again if you take a 440 and put a stage 1 in it, it turns it into a tractor instead of a high end screamer. Even with the stage 2 cam and aggressive porting my 416EX still has monster torque.. I very rarely use first gear. It definitly revs out more than it did with the stock bore/cam, but I don't know if the EX will ever rev out like a 450 or even a Z. I just accepted the fact that the power comes on and drops off earlier on the EX.. I really like how broad the powerband is on mine now though.

[tigerdog]

If you want to move the power there are alot of ways to do this, but i would personally try gearing first in an attempt to broden power in each gear . its a cheap place to start.:)

[Toadz400]

I'd say play with the gearing and it'd probably help a lot if you went with a Stage 2 Hotcam and lightened your flywheel.

[cals400ex]

i got a lightened flywheel forsale if you want it.