lightened flywheel

[cals400ex]

hello, i have asked this before but i want to get as many suggestions as possible. i am considering lightening the flywheel on my 400ex. i understand it may stall a bit easier but that isn't an issue. how much of a gain do you notice with this mod? gt thunder said i wouldn't gain anything in the upper gears but it may accelerate a bit better in the lower gears. also, who does this? i think TC and rocky ridge does this. i don't want to wait a year for it to come back though. any suggestions would be great.

[TC440EX]

Just got my 440 back together and did lighten the flywheel 7oz. Made a big difference in throttle response and not having any problems with stalling. We could take more off but only if we were going to be sand dragging. We did it ourselves in our machine shop, but someone like C&D Racing should be able to help you.

[Big - D Racing]

Every engine builder I know of can do this mod, just check around with local shops

[04hmf400]

Tom miller motorsports did mine and I had it back in about two weeks. This mod was well worth the $50 dollars it cost.My bike seemed to have more bottom end after this was done. I did not have trouble with stalling.In a drag race it would pull three bike lengths on a bike that would before the mod out run me:D

[Rico]

Just do it damit........:devil:


There are no negatives to doing it only postives. I had mine done 3+ years ago and I have no regret in doing it. Your basically getting faster revs from the motor down low.

Rocky Ridge did mine...:cool:

[cals400ex]

i guess i will do this then.

well, how much should i take off? or should i talk to whoever i sent it too about the amount removed? you don't know what it cost at rocky ridge do you rico?


how much did tom miller take off yours?

[TRXRacer1]

Anybody have any pics of a lightened flywheel?

[UglyMotha™]

i had mine done by rocky ridge i didn't tell them how much to take of or what i just told them i wanted the flywheel mod, and they pretty much took a crap load off, they shaved this sucker from every angle you can see even the face and the back step down was even shaved but it made a huge difference in acceleration, she accelerates quite a bit quicker you not goin to notice any low end power the only thing this mod does is allow the motor to rev quicker, i do however have trouble with idleing, she doesn't like to idle but nothing to worry about in my oppinion heres a pic of mine


http://www.imagestation.com/picture/sraid107/p01f423d48c2b42d9fc91cace5db2711b/f967bfc2.jpg

[TRXRacer1]

Awsome! Thanks man. Would this be a good mod for a mid range machine?

[cals400ex]

this makes the idle rougher?? just wondering because mine doesn't like to idle as it is now. :mad:

it almost seems as if there is an air leak somewhere. i took off both air boots and inspected them. i even bought another air boot that connects the carb to the head. i then removed that little white plastic tank that connects to the air boot and the engine. i think it is for gas recirculation or something like that. none of the hoses or air boots are cracked and all clamps are tight. i then replaced the crush washers in my head so i knew those weren't leaking. i then changed carbs. still no luck. i don't know why mine doesn't like to idle. my buddy had the same setup as me and his was fine. i then even used his carb and it works great on his bike, mine still had a rough idle. i mean, it idles, but it just isn't smooth like his.

[UglyMotha™]

an aggressive cam will cause a motor to lobe and after i put the stg2 in in mine it caused the bike to lobe a great deal, the idle is never consistent, and then after i did the flywheel if you go to give it the gas when the idle is at it lowest it somtimes will stall

[cals400ex]

Originally posted by UglyMotha™
an aggressive cam will cause a motor to lobe and after i put the stg2 in in mine it caused the bike to lobe a great deal, the idle is never consistent, and then after i did the flywheel if you go to give it the gas when the idle is at it lowest it somtimes will stall


yeah, mine did that too. if i leaned out the fuel screw it wasn't as noticable though. just something to try.

[Rico]

I have no idle problems. She purrrrrrs like a kitten...:D

[turnandburn]

has any one noticed that with a lightened flywheel your front end acting different after a jump take off. On mine it seems like if i dont attack the jump on the gas the whole way the front end dives like if i keep the throttle at the same spot. I know if you let off it will cause the front end to drop,didnt now if the front end seemed more sinsative.

[cals400ex]

Originally posted by turnandburn
has any one noticed that with a lightened flywheel your front end acting different after a jump take off. On mine it seems like if i dont attack the jump on the gas the whole way the front end dives like if i keep the throttle at the same spot. I know if you let off it will cause the front end to drop,didnt now if the front end seemed more sinsative.


i dont' see how a flywheel would be able to do that.

[K_Fulk]

Originally posted by turnandburn
has any one noticed that with a lightened flywheel your front end acting different after a jump take off. On mine it seems like if i dont attack the jump on the gas the whole way the front end dives like if i keep the throttle at the same spot. I know if you let off it will cause the front end to drop,didnt now if the front end seemed more sinsative.

Ive noticed mine has started to do that but i figured my shocks need serviced. Just noticed it the last couple weeks. But i havent rode on this motor a whole lot either.

The rebound adjustment wont take it out. Its made for a few scarry situations.

[TC440EX]

It's called "INERTIA''.

[turnandburn]

glad i am not the only one. i have had a few close nose dives. The last one i half way saved till my right foot slipped of the peg and the quad ran my leg over,heel gaurds on now!!