fly wheel

[400exshop]

Can some one tell me where to get my fly wheel lighten up. And what is a good price to get it done ?

[Red_250EX_Rider]

Originally posted by 400exshop
Can some one tell me where to get my fly wheel lighten up. And what is a good price to get it done ?

I may be wrong but I thought you just bought a lighter flywheel off a after-market company. I could be wrong so wait for someone with more experience.

Edit Nvm you do light it up :P

[JOHNDOE83]

someone posted this on my "home made hood" thread, I think these would be the guys to call?

www.davemooreracing.com

[honda400ex2003]

also this guy could be doing them still or at least able to do them.

http://www.exriders.com/vbb/showthread.php?s=&threadid=420153&highlight=flywheel

steve

[anderson3064]

i am kn ow expert but i was under the impression to have a heavier flywheel to keeps its inertia when coming out of corners to get back RPM's quicker.

[honda400ex2003]

correct in some ways. The heavier the fly wheel the better the lug capability of it since it keeps the inertia going better. it will not rev as quick though.

the light one will rev quicker but will not be able to lug as well. for his situation, he could probably get 16 oz off or more and be plenty fine. I plan to do 12 sometime to my spare one that i have and will be trying it out on the 416 this spring and the 440 after that.

steve

[PaRedneckRiders]

Originally posted by anderson3064
i am kn ow expert but i was under the impression to have a heavier flywheel to keeps its inertia when coming out of corners to get back RPM's quicker.

the lighter the flywheel the quicker the rev because there is less rotating mass.

It is alot easier to lugg around a motor with a heavier flywheel because there is more rotating mass so you can run low rpms with easy throttle instead of cracking the throttle and have a really quick rev.

So lighter flywheel= faster reving better for drags and some MX racing

Heavier= slower rev but not as much of an explosive power so better for trails/ woods riding.

[PaRedneckRiders]

Originally posted by honda400ex2003
correct in some ways. The heavier the fly wheel the better the lug capability of it since it keeps the inertia going better. it will not rev as quick though.

the light one will rev quicker but will not be able to lug as well. for his situation, he could probably get 16 oz off or more and be plenty fine. I plan to do 12 sometime to my spare one that i have and will be trying it out on the 416 this spring and the 440 after that.

steve
Dang you beat me 2 it

[honda400ex2003]

gotta be quick to get one past me. if i am on or not. lol steve

[400exshop]

I have a extra bottom end so i was going to try it out. If it not what i need for the 440 ill put it on the 426 that we are going to build next.
With the 426 we are going to try and beat the 440. the 440 has beat ( 3 ) 460 in the dirt and at the drag 1/8 mile. And it was on motor .
We run on nos just to see how bad we sould beat him and it was like 4 bikes. on motor it was like 1 1/2. the last 460 we ran was built bye sparks.
I now think the 426 is he way to go now with light piston cp or je. From what i have read cp is the better one.
Thin have the crank lighten up , fly wheel lighten up, under cut the tranny not override they have to manny probs.
Then this will make for a nice tt motor or drag motor.Ps must go 13.1 on the comp to help on the bottom end now that we have lighten up the crank and fly wheel.

[jensenracing77]

in my opinion, the 400EX has way to much mass to it's flywheel. i would even cut it for woods riding. even after cutting it down it will be over 4.5 lbs.

[Thumpin440ex]

I have read of this, but not to much feedback, from guys that have them done( or at least I have not seen it) Will this be a noticeable diff over the stock one, as far as feeling the power, or just hearing the engine.. I have no problem, if I have to rev slighty more in the woods, if it will benifit the overall acceleration, hp... Not actually sure if it will hurt tq numbers, because it will in turn be able to rev faster.. Sorry to hack, but this might help more then just myself out..

John

[jensenracing77]

Originally posted by Thumpin440ex
I have read of this, but not to much feedback, from guys that have them done( or at least I have not seen it) Will this be a noticeable diff over the stock one, as far as feeling the power, or just hearing the engine.. I have no problem, if I have to rev slighty more in the woods, if it will benifit the overall acceleration, hp... Not actually sure if it will hurt tq numbers, because it will in turn be able to rev faster.. Sorry to hack, but this might help more then just myself out..

John
the best way to explain it is to say a flywheels purpose is to store energy. the peek torque and horsepower will not change (well maybe a very slight amount but not worth noting) but it is relocated in the RPM range. the heavier the flywheel is the more energy it will store and also take much longer to fill it with energy. also with the heavy flywheel, when you let off the throttle it will release this stored energy and keep the engine spinning much longer. if you make the flywheel lighter it will fill with energy much faster. this energy that don't have to go into the flywheel is now used by the load on the engine. this puts you into the power of the engine much faster and also makes for much faster response to your throttle input. this will also add to the engine braking affect on deceleration, and even more so with added compression. with less stored energy it don't have to release as much and the engine will decrease RPM faster.

on the 400EX i strongly recommend stock crankshafts and rods when you use a cut flywheel. the stock crank will hold much more RPM and not hurt a thing. i know of stock 400EX cranks spinning 11,000 rpms regularly for years and not hurt them.

you will notice a nice difference on a stock engine but it is really noticeable on an engine with 10:1 or higher compression and a cam. you will be happy with the outcome.

[Thumpin440ex]

PM SENT

John

[dc01]

How much do you take off?

[jensenracing77]

don't know the exact amount. around 1 lb

[sneaky11]

How much u could drop the weight on the flywheel w/o hurting the starter and passing to kickstart?

And if i take 1lbs on it, did it need to be rebalanced? or it' pretty good to go?