How much to lighten a flywheel?

[Giz400ex]

Does anybody know how much it is to have a flywheel lighten???? Thanks

[sikblak400]

is it hard to get an flywheel off? is it worth getting it lightened? what kinda preformance gains will you see?

[cals400ex]

$50 from gt thunder. i heard it was a decent mod. they said no major difference but everything helps. i am going to try it since i don't do trail riding and high rpm power is important to me. i just need to send mine off. i will send it off this this week. i probably won't install it until mid to late december so i can get my finals out of the way at school.

[Giz400ex]

Originally posted by cals400ex
$50 from gt thunder. i heard it was a decent mod. they said no major difference but everything helps. i am going to try it since i don't do trail riding and high rpm power is important to me. i just need to send mine off. i will send it off this this week. i probably won't install it until mid to late december so i can get my finals out of the way at school. ok, thanks Cal!

[speedy400]

cal, you said this would be usefull for you because you dont do much trail riding. I'm just curious, why would you not want it in the trails? thanks-darren

[Fred55]

With a lightened flywheel, it makes the engine rev faster, BUT it also makes it a lot easier to stall. A heavy flywheel is what some people get for the woods to keep the quad from stalling so much and it also smooths out the power delivery.

[cals400ex]

that is correct. many of the woods riders or people wanting all the bottom end power prefer stock flywheels or even adding weights to the yfz's so they don't stall out as easy. the few people i talked to with lightened ones on a 400ex said it didn't stall out any easier. one person said the idle was a bit more irratic though. i sure don't need that.

[wilkin250r]

We all know the concept of ineria, right? It's harder to get a heavy object moving fast, but easy to get a light object moving fast. It doesn't increase or decrease the maximum speed, it's just easier/faster to GET to that top speed.

Rotational movement follows the same principles, but actually has a greater effect. So a lightened flywheel will allow an engine to go from 1000rpm to rev limit much quicker, but it won't increase the rev limit. So a lightened flywheel will not increase your top speed, but it WILL increase your acceleration.

During the compression stroke, the piston is compressing the fuel/air mixture, which requires energy. The pressure is increasing, which is pushing back at your piston. It is the rotational momentum of the flywheel that provides this energy to compress the fuel/air mixture. With a lightened flywheel, you decrease this energy, so your quad is much more likely to stall.