Reduce engine braking on 2012 WR450

I know one thing for sure. If I owned a fuel injected model I would be all over any published and suggested maps prior to other mods other than opening it up. It's the logical way to begin unless you know where you want to go as in you are a professional tuner or you really know what you are doing.

Exactly what any reputable dealer would do when they add an aftermarket exhaust. And what I did to my KTM.
Just checked my TPS reading. My D:01 reading is 11 with the throttle closed.

 

It might work better to set it to 16.  On the WR250R, some guys said it helped a little to set the TPS to the upper part of the range.  I guess they figure if you set it at the minimum, there's a little lean spot where the throttle starts opening but the fuel stays at the idle mixture.

Edited by cracker please

 

One other thing I did to mine is smooth out the flow over the cold start button plunger.

 

See this:

 

I didn't use a piece of cork.   I used the epoxy gum that is used to seal fuel tank leaks.

 

A lot of times when I pull in the clutch while rolling, I get what I'm assuming is a flameout.  Usually I can pop the clutch and get it going again, but every once in a while it doesn't work.  I might give that one a try if I can unscrew the plunger without too much trouble. 

 

I'll give it a try next time I have the valve cover off.  No room to turn the wrench.

Edited by cracker please

Answer me this, GP1K.

 

Does a bike with an aftermarket exhaust run with the FMF map ?

 

Does a bike with an aftermarket exhaust run with the woods map ?

 

If your theory is true, how can that be ?  You tell me that a bike with an aftermarket exhaust can't run with the stock map (all zeros) let alone the woods map.   And if the woods map doesn't harm a bike with an aftermarket exhaust, how can the stock map (all zeros) be bad for it ?   Are there special combinations of fuel and ignition ?  I don't think so.  Yamaha didn't tell us about that if there is.

 

So please stop insulting and criticizing and EXPLAIN TO US HOW THE FUEL INJECTION SYSTEM ON THE WR450F works.  Now is your chance.

 

If you made major changes to intake & exhaust on a carb'ed bike, would you not change the jetting to compensate? Simple question, yes or no?

 

If no, you're truly clueless and we can just stop right now. If yes, then why would think the same would not be true with an FI bike? Oh right, because you think it works like FI in car, which in fact it does not.

 

I get it that you don't understand how the FI mapping works, and how different maps affect the bike with different mods. Perhaps if you put all your great powers of internet research to bear, you could educate yourself on the subject and stop making a fool out of yourself.

Sooner or later other people are going to start testing this stuff and reaching the same conclusions that I am and you are GOING TO LOOK LIKE A FOOL.  But keep shoveling away.  Keep arguing everything is wrong and calling names.   Better trade that WR and 250F off on that KTM 350F so you can make a graceful exit from here !  LOL.

 

Just had to quote this again for posterity because it's so awesome. Yup, I'm gonna look like a fool any day now... the bike has been out nearly 3 years, but one of these days everyone will see the true genius of MLCG's mods and everyone will jump on the YZ cam bandwagon. Bwahahahahaha :goofy:

Because I forgot to read the bible that the parishioners on this forum worship.

 

Because I'm an independent thinker.

 

Because I decided to change the exhaust cam while I was checking my valves.

 

Because I didn't mind the stock map and wanted way less exhaust braking and I didn't see the map as doing that.

 

Because I wanted to experiment with cams.

 

AND I DID !  AND IT WORKED !

 

FWIW, I'm not the one fooling around with a programmer asking for more low end snap, less exhaust braking and less throttle sensitivity.   I'm the guy that is saying my bike works way, way better than stock.  I don't think its a coincidence that I changed my exhaust cam and the other guys are fooling around with programmers.

 

It worked? How do you know exactly? Did you run before & after dyno tests? An air/fuel analysis? Any actual DATA to support your claims besides your feelings and opinions, as a first year rider? Yeah, didn't think so. YOU HAVE PROVEN NOTHING!!!   You can't post ride vids to show how awesome sauce you and your super duper modded bike are. You're a hack and fraud.

Boy, thats a first

TOO MUCH engine braking?

I thought that was why a 4 stroke engine was good

I'm having a hard time getting my head around the idea of too much....

Boy, thats a first

TOO MUCH engine braking?

I thought that was why a 4 stroke engine was good

I'm having a hard time getting my head around the idea of too much....

 

Too much is when even at moderate RPM when you let off the throttle there is severe engine braking which pitches the bike forward, makes the fork dive and upsets the suspension. Better to control your suspension with the brakes vs engine braking.

you like trials type riding so you de-tuned and geared your bike so you don't have to ever touch the clutch?   lol

Edited by DRS

I like engine braking. But I'm coming off a XR650. But for huge down hill descents I let the bike do the work. And is it me? If I was doing tight woods riding wouldn't I want to be on a YZ with a tighter gear box?

It runs

 

Isn't that enough?

 

Who cares if it's running hot, lean, WITH non-linearly.

Who cares if there is tons more throttle response to be had. 

I KNOW it's the best it can be, because I'm very senstive, and I read everything I can, that supports my point of view.

 

I know I'm not wrong, even though the defective brain that got me to this point is the same brain I am using to determine if I am correct.

 

Changing maps is for PUSS-Y'S. 

If I was doing tight woods riding wouldn't I want to be on a YZ with a tighter gear box?

 

Anyone make a 10 tooth countershaft sprocket? :goofy:

Too much is when even at moderate RPM when you let off the throttle there is severe engine braking which pitches the bike forward, makes the fork dive and upsets the suspension. Better to control your suspension with the brakes vs engine braking.

Agreed.  My 05 wr had too much and would completely throw me off balance at times.  Clutching while backing off the throttle would lessen the sensation.   But when I was tired, I just didn't do it because...   well... I was tired.  It made for some slow and crappy riding on my part at the end of a long riding day.  

I upped my CO # to 7. And used the following map.

 

Fuel    Timing
3 4 4     0 0 0
3 5 3   -2 -1 0
3 4 3   -2 -2 0

 

This has completely removed the twitchiness the bike had when going from 1/8 throttle to 0 throttle.

 

Thanks for everyone's help.

 

 

My bad for describing the problem as engine braking. For what it's worth, I believe the engine braking is still the same. Which is fine with me.

Good to see it worked for you.  I'm running virtually the same, with a  CO of 8.

I upped my CO # to 7. And used the following map.

 

Fuel    Timing

3 4 4     0 0 0

3 5 3   -2 -1 0

3 4 3   -2 -2 0

 

This has completely removed the twitchiness the bike had when going from 1/8 throttle to 0 throttle.

 

Thanks for everyone's help.

 

 

My bad for describing the problem as engine braking. For what it's worth, I believe the engine braking is still the same. Which is fine with me.

 

Glad my vlxjim map worked out for you. When I made that map the goal was to have smooth trackable power. With better control at the bottom.

Enjoy

Jim

More overlap reduces dynamic compression.

 

I think I was wrong about this.  Increasing overlap reduces vacuum at lower rpms.  That's where the reduced engine braking would come from.  Leaving the exhaust valve open longer should pull more intake in at high rpms, that would mean more compression.  But usually the intake cam is a little bigger than the exhaust cam.  A lot of the extra intake charge might just be blowing out the exhaust unburned.  I guess intake valve closing would have the most effect on compression.

Edited by cracker please

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