06 ignition on an 09, anyone try it ?

Why a flywheel weight? Defeatng the purpose of installing the 06 cdi.
Not in the least. I have a GYT-R off-road flywheel on my '06, and if anything, it pulls harder at low speed with it than without it. I'll guaranty there's no loss of performance.

As was pointed out, the quad engine is a low power version of the WR. It's down about 8hp to the YZ, and comes with a flywheel 3 times the size of the YZ's flywheel. The YZ450 flywheel is smaller than the gas cap, and weighs next to nothing.

Not in the least. I have a GYT-R off-road flywheel on my '06, and if anything, it pulls harder at low speed with it than without it. I'll guaranty there's no loss of performance.

As was pointed out, the quad engine is a low power version of the WR. It's down about 8hp to the YZ, and comes with a flywheel 3 times the size of the YZ's flywheel. The YZ450 flywheel is smaller than the gas cap, and weighs next to nothing.

OK Gray, we are going to have to agree to disagree on this one. From all my experienc and others that I know have the opposite experiences. More flywheel weight will make the motor rev slower than with a lighter flywheel.

With all that said, our main goal here is to find out if the 06 cdi on an 09 with stock 09 cams will enhance or make the low to mid part of the rpm range more snappy. With my quick testing on flat ground I say yes. Plan to ride on the trail soon.

But your experience it with quads. . .

From all my experienc and others that I know have the opposite experiences. More flywheel weight will make the motor rev slower than with a lighter flywheel.

But, you have no such first hand experience with the YZ450, do you? The experiences you had were with engines having relatively heavy flywheels. The YZ450 flywheel is simply insignificant as part of the engine's rotating mass, and the engine itself, while it does rev quite freely, has so little rotating inertia that it actually looses net output below about 4000 RPM. Comparing my two '06's side by side before and after the flywheel on mine confirms this. They ran dead even before, and they run dead even now, except mine pulls harder and smoother at low speeds now than my son's bike.

http://www.thumpertalk.com/forum/showpost.php?p=9215464&postcount=53

I was gonna say the same thing Gray...if an engine has a heavy FW weight already, then adding more weight could hinder performance...but an engine that has a paperclip as a FWW can be improved by adding some mass.

As for the rest of the story......on the 06 cdi......on the YZF NOT YFZ. What the verdict now Gunner? Any more blind comparisons?

My real world experiences seem to be not worth much here. So I'll just keep all the information and experiences not posted here. Good luck!

Sent from my iPhoneuck.

My real world experiences seem to be not worth much here. So I'll just keep all the information and experiences not posted here. Good luck!

Sent from my iPhoneuck.

Some of us are still interested in your experience and information on this topic.:banana:

I have not said your experiences weren't worth anything, only that they didn't apply directly to the YZ450 because of that machine's specific idiosyncrasies. It's a shame you've taken that attitude.

Its all good dude, we want to know how did it turn out? I am leaving in about 3 hours to pick up a 2009 with about 15 hrs and full DRD exhaust. Tell me more!!!

I rode my bike today at a local high speed track. I rode it with the 06 CDI first and could immediately tell the bike had more low end snap. I then put on the 09 CDI and it felt slower and I had to carry more speed on the jumps right out of corners to clear them. I didnt notice any loss of overrev. This was a great $40 investment.

That's what I thought you'd say. Thanks for the feedback.

Not in the least. I have a GYT-R off-road flywheel on my '06, and if anything, it pulls harder at low speed with it than without it. I'll guaranty there's no loss of performance.

As was pointed out, the quad engine is a low power version of the WR. It's down about 8hp to the YZ, and comes with a flywheel 3 times the size of the YZ's flywheel. The YZ450 flywheel is smaller than the gas cap, and weighs next to nothing.

I think its scientifically not possible to add rotating mass to an engine and not cause a loss of power.

It's still off the original topic, but it's true that on a theoretical basis, added rotating mass will require more energy to accelerate than a lesser mass. It will not require any more power once at speed, however. But again, from a completely empirical standpoint, wherein the performance of a weighted YZ450 was compared to an unweighted one, and against its own previous unweighted performance, there was no noticeable loss in acceleration. The benefit to this particular engine from the added mass at low RPM is very noticeable, however, because the as-built rotating inertia is so low. And that's not theory.

TT member DPW, and a number of others will agree, speaking from experience.

You may want to read:

http://www.thumpertalk.com/forum/showthread.php?p=9215464#post9215464

It's still off the original topic, but it's true that on a theoretical basis, added rotating mass will require more energy to accelerate than a lesser mass. It will not require any more power once at speed, however. But again, from a completely empirical standpoint, wherein the performance of a weighted YZ450 was compared to an unweighted one, and against its own previous unweighted performance, there was no noticeable loss in acceleration. The benefit to this particular engine from the added mass at low RPM is very noticeable, however, because the as-built rotating inertia is so low. And that's not theory.

TT member DPW, and a number of others will agree, speaking from experience.

You may want to read:

http://www.thumpertalk.com/forum/showthread.php?p=9215464#post9215464

I agree 100% am I sure many others do too. I think one main reason that the bike "feels" faster is it is gettting a LOT better traction so its gets better drive out of corners and such instead of just spinning.

I agree 100% am I sure many others do too. I think one main reason that the bike "feels" faster is it is gettting a LOT better traction so its gets better drive out of corners and such instead of just spinning.

If your saying that a FWW can help correct poor throttle control then I would have to agree but it is not possible for added weight to increase power.

Getting back on the subject at the request of a couple of members via pm's. Had a chance to ride today with the 06 cdi in two 09 450s. The 06 cdi is like adding a high compression piston feel. There is a noticeable hit or bark right off idle. Very manageable and just what I was looking for. Lot easier to snap the throttle and lift the front end up over obstacles. This mod gets two thumbs up from me and my son in law.

Edited by Gunner354

It would be nice to know if any other year cdi would give the same affect. If someone has

information on the exact timing curve on all years that would be great.

Edited by Gunner354
It would be nice to know if any other year cdi would give the same affect. If someone has

information on the exact timing curve on all years that would be great.

That sure would be nice, gathering up info on CDI's from 06-09 and seeing what kind of timing curve each one has.

If your saying that a FWW can help correct poor throttle control then I would have to agree but it is not possible for added weight to increase power.

Did you read my post? or Grayracer's?

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