Why do I have to buy a Power Tuner?

[swaldrop]

Just got an '11 and, like many people have said, the off idle power is incredibly abrupt. I am having a really tough time keeping the wheel from spinning. I am coming off of an '08 (with an '06 stock pipe) that I felt had really great power, top and bottom. Just having a tough time getting used to this new one.

Getting back to my question... I don't want to spend $250 on a tuner that I will use once. I have heard great things about the Jay Marmont map and would gladly run it for the rest of the time I own this bike. Once I find the sweet spot, I don't foresee ever wanting to change the power. The terrain I ride never really changes, and even if it does, I can't imagine ever wanting that hit back.

Anyone in the Central Florida area have one of these that I could use? I would certainly be willing to pay you for the privilege.

Thank in advance.

[zukboy789]

You need the tuner. Its just another way for Yamaha to make money.

[vade]

Isn't FI great!!!! lol

[brentn]

You'll use it more than once. I use mine all the time to check running time, air and coolant temp for outdoor condition monitoring and timing adjustments.

The fuel and timing I admit I only dinked with once, but the tool is also used for checking error codes.

You'll kick yourself in the nuts when you start doing your own diagnosis on a faulty part that could have easily been identified by plugging in the tuner and checking the code.

The off-idle lunge in power is a known issue and confirmed with most riders, especially ones using it for slow stuff like trail riding.

This is a throttle body issue and not a map issue, you can't "blend" it out with fuel or ignition changes.

If your going to spend 250$ hoping that will fix your problem, you'll be very much disappointed.

Injectioneering will modify your throttle body to cure the issue.

[swaldrop]

The off-idle lunge in power is a known issue and confirmed with most riders, especially ones using it for slow stuff like trail riding.

This is a throttle body issue and not a map issue, you can't "blend" it out with fuel or ignition changes.

If your going to spend 250$ hoping that will fix your problem, you'll be very much disappointed.

Injectioneering will modify your throttle body to cure the issue.

Well, maybe I used the wrong terminology. FI seems to have introduced a few more buzz words in to the MX world...

My issues with the power come to light mid corner, when I am getting back on the gas. I find it hard to keep the wheel from spinning. I have heard that with the tuner, you can tame down that low end grunt and broaden the power a bit. I also notice the lack of top end as well, but that doesn't bother me as much as I can shift to overcome that. Just need to get that bottom end tamed down a bit.

[brentn]

Yes maybe we are talking about two different things.

If your looking to reduce the torque down low and your not talking about instant throttle opening issues then the tuner will help.

[HRC]

I will get my power tuner maybe next week, but I am a little curious about this Jay Marmont map.

Can someone tell me how this map changes the powercurve compared to stock ? What is it that becomes so much better ?

[SEOINAGE]

You should be able to reduce torque in that off idle range by retarding the timing.

[tech24]

You should be able to reduce torque in that off idle range by retarding the timing.

+1 I use woods map and a G2 throttle tammer for offroad. This combo really helps. The instant "lunge" is gone. However its something you will get used to not even notice with some seat time. I use different maps for the track and am getting the G2 quick open cam for mx as I have came to like the off idle get up and go.

[ttr250dude]

Correct me if im wrong, but the fi bikes use an oval throttle cable mount thing thats on the throttle tube. The oval makes the throttle open quicker on initial throttle turn. Swap it out for the old style round one, that might help.

[brentn]

Correct me if im wrong, but the fi bikes use an oval throttle cable mount thing thats on the throttle tube. The oval makes the throttle open quicker on initial throttle turn. Swap it out for the old style round one, that might help.

second time I've heard mention of this, what are the details here?

[grayracer513]

Haven't looked that close, but it looks pretty round to me.

The real fix for this is the mod Injectioneering is doing, in which the angle of the closed throttle plate is changed.

[ttr250dude]

second time I've heard mention of this, what are the details here?

These are COMPLETELY random numbers but it should get the point across: With the oval, if u turn the throttle half way it will open up the carb 3/4 open. With a round one, when u turn the throttle half way it will open the carb half way. Not sure if i expalined that correctly and again these are random numbers but it should get the point across.

[ttr250dude]

This is what i mean

http://www.bikeeffects.com/proddetail.asp?prod=40-400

So on initial throttle movement it opens the carb more than a round one would.

[tech24]

The stock throttle tube is the same as any YZ. Its the trottle body itself that is egg shaped and the pivot on the butterfly is off center causing a faster opening speed. This is changed with the injectioneering mod. I have the G2 system with all the available cams and it is a nice piece but not as good as having the t-body mod however its not permanent.

And the one in the pic is the 400 adapter which is the slowest opening speed, 25 is the fastest and its got a fat part at the begining.