Hey, I talked to you guys before about the sluggish low rpms performance on my new F4i. I had the stock pipe rearended. I exchanged it to the Two Brothers M-2 . It sounds and looks like a rocket with it.
http://youtube.com/watch?v=yBCRrPqWzuA

But.... It did not eliminat this vastly annoying Flat spot in the 2-4K rpms. You know when you in a traffic jam, and you want to quickly move and switche from lane to the next one, or simply avoid somebody driving right into to you , you twist the throttle and you should be riding off .
When I do that, I hear the bike guzzle and buzzle and choke when it get more gas from the injectons, but it's not moving . I ride low gears ( this is happening in the 1 n' 2 ) I am so disapointed , saddend and I must say really annoyed with this. The headers are 100% no kinks . I would like to see this model to be smooth the whole time. I mean I know you can -1 / + 2 n' stuff but that's not gonna eliminate the engine flat spot .

Will the PowerCommander, with the correct map from twobros.com fix this ? Should I be looking at the K&N air filter as well , or stay with stock. I must eliminate this , pleaseeeee help ) The bike has already been broken in , btw.

You guys have the same problem with you fuel injected vs. carbourated F4i's ?

Philnyc

 

If you rip the throttle and your rpms go up and you don't go anywhere. It sounds like your clutch is going out. I had that happen to me. I replaced my clutch and it took care of the problem.

 

I don't think it's the clutch . It's has to few miles on it. I don't abuse the gearbox nor the clutch .
I just came back and tested the bike on an empty parking lot.

This is the scenario: 1st gear go. left off the throtle let it idle while moving ( my idle it set at aprox: 1200 rpms) ;
I twist the trothle open and then the bike starts to choke and guzzle all that until it slowly ( about 1.5 secs reaches above the 3-4K rpms) Then is accelarates as normal and as expected.

The same thing happends with the 2nd gear.

You guys have the same like this or there's defenetly something wrong ? What is wrong ?

Thx
Phil

 

It's a 600, it's going to be a dog until you reach higher RPM's.

 

Mine does the same thing. Seems that when it hits exactly 2500rpm it just takes off like i pushed a button. Night and day. I know everybody is sayin that this is normal and its cuz it's a 600 but my buddy has an 06 f4i w/ yosh pipe and his does not do it. me and him were going like 30 and we both put em in 6th and he took off from me while mine was still spitting and spuddering until 2500. I have a D&D pipe and that's it.

 

I am not a big fan of the power commanders, but it does sound like you have a bit of a problem and maybe a good custom map would help.. My bike is a dog to down low, but it doesn't struggle, it is just slow and smooth. All these bikes are built within tolerances, maybe yours is close to being an outlyer.

 

fishflyer , I have exact same bike as you do. what the hell ? You called it man: mine struggles... Good custom map . o boy , there goes the 150 + the commander ....

 

I've got an '05 F4i with an Akra slip on and I get perfectly smooth response from the bottom to the top!(No sputtering, coughing or flat spots of any kind!)You must have something wrong with your bike. I don't think you can account for it simply because it's a 600, or an F4i! The fuel injection should be perfectly smooth - isn't that the whole point?

 

Ideally, but the F4i is a first gen. fuel injected bike. It's not perfectly smooth.

My bike is weak in the 2-4k rpm range as expected, but i don't have the sputtering issue. Maybe remap? If it's new i'd see if the dealer could flash it or something.
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PORTABLE VAPORIZER

 

oh and the only time mine coughs or sputters is when im at or below 2500 and giving it over half throttle. its not really bad but i can definately tell something is not right.