Lightweight flywheel

[smoke tractor1]

I know this has probably been beat to death but wondering who does the best at flywheel lightening for 400's!

[honda400ex2003]

try to find a local fab shop to do it for you. it would be easier than sending it out to have done as long as they do a good job of it. speedfreek username on here said he would do them a while back but I am not sure if he would still be interested or not. at least that is a couple of options for you. steve

[atv fan 28]

Dave Moore might be able to help you out.

http://www.davemooreracing.com/Flywheel.html

[honda400ex2003]

theres some sick stuff on that site! steve

[jensenracing77]

i do them for $100. that is with return shipping included. i have little to no posts here so i understand that i have no history with you all. i have no idea how much others are charging. also, most people don't cut them from the center line like they should.

[smoke tractor1]

I would like to see a pic of one, if you have any!I'm on a slow build, I have until very late winter to finish,but can send you a stock one! Thanks Shane 865-335-3791

[jensenracing77]

the only one i have is in my engine. i may have an extra one i can cut to get a picture. i will have to look. i think TC racing does them for about the same price but he can be slow sometimes.

[jcs003]

ricky stator has rhem for about $125

[BombSquadEx]

Im not trying to offend you jcs by saying this,
but ive looked over ricky stator's website and i
cant seem to find a flywheel for the ex.

Hopefully its not something im overlooking,
If you have a link that would be quite helpful!
Thanks.

[jcs003]

Originally posted by BombSquadEx
Im not trying to offend you jcs by saying this,
but ive looked over ricky stator's website and i
cant seem to find a flywheel for the ex.

Hopefully its not something im overlooking,
If you have a link that would be quite helpful!
Thanks.

my mistake. they have them for the tecate, banshee and trx250r.

[MtnEX]

How much can you lighten one without hurting the crawling ability?

Or are they so much heavier than say a 450 flywheel that you really can't cut them to that extent?

[jensenracing77]

Originally posted by MtnEX
How much can you lighten one without hurting the crawling ability?

Or are they so much heavier than say a 450 flywheel that you really can't cut them to that extent?

they are way to heavy on the 400. i don't know how others cut them but when i cut them i want the flywheel and the starter clutch all together. i cut as much as can safely be cut. i can't remember how much i cut off of them but think it is close to 1lb. they are still around 4.5 lbs after they are cut.

[honda400ex2003]

imo i wouldnt go much over 12 oz but to keep a bit more crawling ability i would go around 8-9oz. just a couple of numbers i have heard in the past. no personal reference to which is better. I have heard upwards of 14oz-16 oz coming off of them but that would probably start to affect some low end performance while crawling. doesnt seem like much but.... if it really is or not is a different story. steve

[jensenracing77]

Originally posted by honda400ex2003
imo i wouldnt go much over 12 oz but to keep a bit more crawling ability i would go around 8-9oz. just a couple of numbers i have heard in the past. no personal reference to which is better. I have heard upwards of 14oz-16 oz coming off of them but that would probably start to affect some low end performance while crawling. doesnt seem like much but.... if it really is or not is a different story. steve
you can not cut any more off of a 400EX flywheel than i have cut off mine. i have no problem with slow speed "crawling" as you call it. it is not as bad as a stock 450ER, those have almost no inertia at all in the flywheel. i do have much more engine braking. i wish i could cut another 4oz off but there is nothing else i can safely cut. it is incredible how much difference there is in a cut flywheel on the 400.

[honda400ex2003]

you took 16 oz off. i stated that 12 would be a good all around place to stop. 4 oz isnt that much to take off really, it is only a few of passes on the lathe. the 400 has plenty of torque to spare on most engine setups so it should still be plenty fine. the xr ones have more than a pound off of them. buy one of those and put it on or so ive heard you can do. it may require the kick start conversion also since that one doesnt have the teeth for the starter gear on it. another good reason to convert to kick if you want to save more weight. steve

[MtnEX]

Hummm... good info here...


I think I'd want to pick up a spare to have cut... and still be able to go back if it's too much loss.

[jensenracing77]

Originally posted by MtnEX
Hummm... good info here...


I think I'd want to pick up a spare to have cut... and still be able to go back if it's too much loss.
if you do that, you will need to buy the flywheel and starter clutch that bolts to the back of the flywheel. they are both cut on.

[honda400ex2003]

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


steve

[jensenracing77]

i am sure that most of you know this but just wanted to explain what is going on when a flywheel is cut. cutting the flywheel will NOT give you more power or torque but the power and torque that the engine all ready has is relocated in the RPM and gives you access to it much faster. you will notice more engine braking when you let off the throttle because it has less inertia. a flywheel stores energy when you rev it. the heavier it is the more energy it stores but the longer it takes to fill it with energy. when you let off the throttle it unloads that energy and keeps the engine spinning. taking weight off will allow it to store less energy and rev faster because it will fill with energy much faster. letting off the throttle will give you more engine braking because it has less energy to release.

the 450s of all brands have very light flywheels and is a part of why they rev so fast. that in conjunction with there very short stroke. the 450ER has a stroke of 62mm and the 400EX has a stroke of 70mm. this long stroke of the 400EX and a flywheel that is around 5.5 lbs makes it a turd on throttle response. and not to mention how big the diameter of the 400 v' the 450 is. that is why i recommend cutting the full amount off of them. i will say that i have had a couple complaints on the higher engine braking but never on the quicker revving or low speed riding.

[honda400ex2003]

good info for clearing that up. it did seem that were some with an idea of that it will actually increase hp and torque. do you have a lathe to cut them jr? how much you charging to do them? steve

[jensenracing77]

Originally posted by honda400ex2003
good info for clearing that up. it did seem that were some with an idea of that it will actually increase hp and torque. do you have a lathe to cut them jr? how much you charging to do them? steve

to tell you the truth, i don't cut them. i have that outsourced to a local guy that cuts them to my specs. they look scary when you look at them but they are safe and still have enough material to not loose any magnet strength. i charge $100 and that includes the return shipping in the 48 states. i can not give any warranty at all. it is at your own risk, but i have built at least 50 engines with this done and not one problem. if i do them i want the flywheel, stater clutch and retainer, and also still bolted together. i will also add that you will get the same cut flywheel from TC racing that you will from me. he is much more known than me so if you don't want to trust some clown on the net then give him a call.