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ekulb14

Can you reduce engine braking? 2008 yz 450f

60 posts in this topic

hi everyone, so on my brothers 2008 yz450f (stock internals and exhaust ) it has very heavy or aggressive engine braking. We were wondering if there is anything we can do to lighten it up a bit. Basically we are looking to make the bike smoother, my only thoughts were changing the gearing or possibley getting less restrictive exhaust system?

any thoughts? ideas?

thanks

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Stay on the Gas!

I am assuming at this point you are saying this... when you shut the throttle it feels like you are stepping on the rear brake?

Have you compared it to another four stroke? Could it be that you just need to get comfortable with the 4 stroke style?

I say this in confidence you have inspected everything and the motorcycle is in proper working order. You could add a heavier flywheel, lessen the compression, change the gearing, change the cam shafts, and so on.

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ya the bike is working fine, just went to the shop vales checked ect...

yes i have compared it to other bikes, in perticular my 2006 yz450f which feels completley different, my bike has far less engine braking and is a lot smoother all around. The 2008 seems to be much more choppy when accelerating and as kx said its like you are stepping on the brake when you get off the throttle.

I think changing the gearing will be the first step, as its the cheapiest and least invasive fix. really dont want to start messing with the internals just yet.

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a guy was showing me his rekluse and pointed out 3little springsabout 3/4 of an inchlong and round different colors and he said that by changing them motor drag could be alterd. i have no personal experiance with it ,think it was exp model. i was asking about it free wheeling if you backed off the gas going down hill and got the quick lesson lol

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The Rekluse clutches are simple centrifugal auto clutches that engage above a preset RPM, and then disengage below that. While these parameters are adjustable over a practical range, there is nothing within the Rekluse system that I'm aware of that has any way of reducing engine braking. Typically, if you let off the gas in gear while riding, you'll have completely normal engine braking until the engine slows below the engagement RPM. If you roll down a hill at idle in gear, you'll be coasting until you blip the throttle once to engage the clutch, but then the engine will be hooked up again until you pull the lever or slow to an idle.

What you would need to reduce engine braking is a "back torque limiting" system such as those made for SuperMoto and road racing bikes. These generally have a portion of the clutch plates driven through a one-way device like a sprag or a roller clutch so that it holds hard under power but slips some when you decelerate.

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The 3 easiest ways to eliminate engine braking are to decrease the compression of the engine (you will lose power as well), buy a slipper clutch (expensive), or pull in the clutch when you let off the throttle.

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This will be a bit expensive,but MUCH cheaper in the long run.....Buy a YZ250 2-stroke!!!Ba-da-bing!I'll be here all week!Thank you,thank you very much....Hey,I've got an 05 YZ250 and an 07 YZ450F,and I LOVE them both.I put a GYTR heavier flywheel on my YZ250,and it gave the 2-stroke even less engine braking. A hotshot young kid at the track wanted to try my bike and nearly had a heart attack when he shut -off in his usual spot for a corner,and the bike didn't slow down!Obviously,I got the heavier flywheel to smooth out acceleration on the two stroke,but less engine breaking is a by-product of it too.Get a heavier flywheel.....(And no,the heavier flywheel doesn't rob any horsepower ).

Edited by flapwick

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The Rekluse clutches are simple centrifugal auto clutches that engage above a preset RPM, and then disengage below that. While these parameters are adjustable over a practical range, there is nothing within the Rekluse system that I'm aware of that has any way of reducing engine braking. Typically, if you let off the gas in gear while riding, you'll have completely normal engine braking until the engine slows below the engagement RPM. If you roll down a hill at idle in gear, you'll be coasting until you blip the throttle once to engage the clutch, but then the engine will be hooked up again until you pull the lever or slow to an idle.

What you would need to reduce engine braking is a "back torque limiting" system such as those made for SuperMoto and road racing bikes. These generally have a portion of the clutch plates driven through a one-way device like a sprag or a roller clutch so that it holds hard under power but slips some when you decelerate.

You said in your first paragraph what I was referring to. The OP asked how to reduce it, not omit it.

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Reading it again, ....

The Rekluse clutches are simple centrifugal auto clutches that engage above a preset RPM, and then disengage below that. While these parameters are adjustable over a practical range, there is nothing within the Rekluse system that I'm aware of that has any way of reducing engine braking. Typically, if you let off the gas in gear while riding, you'll have completely normal engine braking until the engine slows below the engagement RPM. If you roll down a hill at idle in gear, you'll be coasting until you blip the throttle once to engage the clutch, but then the engine will be hooked up again until you pull the lever or slow to an idle.

...I don't think I indicated a method of reducing engine braking with a Rekluse. I could be wrong....

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So I was installing a new rear tire and checking the bearings today for a race this weekend and it got me to thinking about this post. Some of the more experienced mechanics on here can confirm if my thoughts are correct. An over tightened rear axle nut and or rear axle bearings that are going bad making the decelleration is greater? I guess the front bearings and axle nut could also do that? Maybe a dragging rear brake?

I have an 08 YZ450 and the engine breaking doesn't seen extreme.

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The 3 easiest ways to eliminate engine braking are to decrease the compression of the engine (you will lose power as well), buy a slipper clutch (expensive), or pull in the clutch when you let off the throttle.

How does a "slipper" clutch decrease "engine braking"?

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