Lightened Flywheel - Do or Don't

[charles_in_houston]

I have considered a lightened flywheel in the past but was told that it's for lighter riders. I go 220 without gear. What are the pros and cons of doing something like this? Here are my engine mods.

 

- Aggressive dune porting from RB Racing

- Wiseco Pro-Lite forged pistons

- NOSS Cool Head with 21cc domes

- Ricky Stator adjustable timing plate set to +4 degrees

- V-force 3 reeds

- Modded shift star and pro shift kit

- 370 mains, stock pilots

- Vitos carb needles for ported engines set in the middle

- Vitos T.O.R.S. elimination kit

- UM aluminum airbox with single K&N Filter

- FMF Gold series pipes (came with bike)

- Direct Drive lockup clutch

 

My riding is split almost 50-50 between recreational / competitive MX Cross country and recreational drag racing. I'm sure it would rev quicker but at what expense? (Would it be safe for engine reliability?)

[xLastShotx]

The Pros would probably have to be revving up quicker, the cons would have to be that it would be much more prone to stalling at lower speeds because the lighter flywheel doesn't as hold as much spinning mass to keep the engine running. Thats all I can think of rite now there may be more pros and cons.

Edited February 4, 2007 by xLastShotx

[gipperz]

I'm 227 lbs without gear and have no problems, mine was lightened by booneman. I don't think stalling is a problem with two cylinders. I have heard of that with single cylinders. I believe there is no negative side to lightening the flywheel, I think you'll like it. Just my thoughts.

[Big Mike NY]

I had this conversation with my bike mechanic the other day. He said that there is a possibility that if they are lightened too much or incorrectly, they have the tendancy to fall apart at high rpm... Anyone ever have this happen, or hear about it happening?

[Snopczynski]

I have considered a lightened flywheel in the past but was told that it's for lighter riders. I go 220 without gear. What are the pros and cons of doing something like this? Here are my engine mods.

 

- Aggressive dune porting from RB Racing

- Wiseco Pro-Lite forged pistons

- NOSS Cool Head with 21cc domes

- Ricky Stator adjustable timing plate set to +4 degrees

- V-force 3 reeds

- Modded shift star and pro shift kit

- 370 mains, stock pilots

- Vitos carb needles for ported engines set in the middle

- Vitos T.O.R.S. elimination kit

- UM aluminum airbox with single K&N Filter

- FMF Gold series pipes (came with bike)

- Direct Drive lockup clutch

 

My riding is split almost 50-50 between recreational / competitive MX Cross country and recreational drag racing. I'm sure it would rev quicker but at what expense? (Would it be safe for engine reliability?)

 

Flywheel lightening is only made up of one decision. Do you want your motor to have more torque, or rev quicker? Rider weight, and all that dont matter, unless you count the fact that you weigh more, and would like the torque that comes with a full mass flywheel.

[dajogejr]

Dave Moore would disagree about "less torque" with a shaved flywheel...and his word is gold as far as I'm concerned...

 

http://www.davemooreracing.com/flywheel.php

 

I say go for it.

[bansheeryder_69]

the whole flywheel thing is a little sketchy to me too......just hack a chunk out of it with a grinder :thumbsup:

[hondasrslow]

have it done by a profesional. you will be happy with it

[Washburn]

I dont think its a good idea unless you weigh a buck 20. Im all or more torque off the start it might not hurt you as bad (still will) at higher rpms but it will of a start espically a slow one +for a hillclimb with no launch room. + they have been known to spider out and bust definatly if you remove more than a few ozs thats sketchy territory. Better carbs, V3s, Timing, smaller domes/milled head, then a greater spark, port work ect.

[Animalman294]

I had mine done by Boony and it never caused any problems for me, and yes it did rev faster and allows you to get into the powerband quicker. Boonman has done litterally hundreds if not by now thousands of flywheels. I really think by now he has the shaving thing down to a science. But you do need someone doing that knows how much to shave off and who has the right taper for the lathe. The Failure rate is extremely low and you should contact him and ask him the questions. I personally think it is a nice mod, but thats me............... :thumbsup:

[charles_in_houston]

Thanks for the info. As always there are two sides to a coin but this time I think I'm convinced it's a good mod. ....then again, just to be on the safe side I've decided to keep my stocker and look at getting a lightened one to throw on. If it doesn

[ToomeySheeLE]

Does anyone have boonemans email, and where is he located?

 

wouldn't mind sending my bitch down to him.

 

Thanks

[dajogejr]

Thanks for the info. As always there are two sides to a coin but this time I think I'm convinced it's a good mod. ....then again, just to be on the safe side I've decided to keep my stocker and look at getting a lightened one to throw on. If it doesn

[dawarriorman]

Its not going to cause you to lose torque, thats just silly talk.

 

It will cause the motor to rev quicker, in both directions. Let off the gas, and it will drop revs quicker. Get on the gas, and it will let the motor rev faster. The more weight in your drivetrain, from the flywheel all the way to the wheels, takes horsepower (and therefore torque) to spin. You drop 4 lbs off your tires, you picked up hp (and tq). Drop a few ounces off your flywheel, you'll gain hp (and tq). Don't forget, hp and torque are directly related, you can't gain hp and lose torque at the same time at the same rpm.

 

As far as low rpm power, who the hell gives a fuck? Its a banshee, there is no power under 6 grand anyways. And if your spending your time trying to gain low end hp, get a 4 stroke.

 

That being said, I really have no desire to spend the time or money to have it done. Plus there is a (small) chance it could fail.