If I run at a steady rpm for a while and let off the bike seems to stumble pretty bad. It recovers pretty quickly but it does it pretty regularly. I have put the display on tach to see how far it falls but the tach doesn't seem to react quickly enough to show it. I'm just wondering if anyone else has experienced this.

 

make sure the throttle is set at correct spacing(about 1/8") so to elimenate the etc kicking in. expain more on the stumbling. looses power, back firing?

 

my 500 efi does the same.
I Do a steady speed let off the throttle and it seems like the rpms decline so low that it stops the motor. on occassions it recovers the rpm and runs good after.

I was told the throttle cable had to much free play, so i tightened up the cable just a hair more from the handle bar adjustment and it was a little to much so i backed it off and it still isnt enough.

You have to watch when you do adjust the cable that you turn the bars full left and right after . and make sure the rpms dont go up or down that was the problem i had after adjustment.

Have to play with the throttle to have the correct freeplay with the correct idle speed. around 1250 or so.

 

It doesn't backfire. You can feel that the motor seems to stall as if it were idiling @ maybee 500 rpm then the idle comes back up to normal. If I'm not mistaken it drive by wire. There is something writen on the throttle saying something to the effect of to avoid stuck throttle that its electronicly controled?

 

Hey make sure the ADC isnt on.

 

<div class="FTQUOTE"><begin quote>Originally posted by: Lacatahoula

If I'm not mistaken it drive by wire. q]

You are mistaken LOL There is still a mechanical throttle cabe. The electric part of the throttle is the Electronic Throttle Control. It's designed to kill the engine in the event of a frozen or otherwise stuck throttle. If it has too much free play in the cable it can also kill the engine.

Back to your problem, mine did kinda the same thing untill I got some miles on it and then it seemed to fix itself

 

<div class="FTQUOTE"><begin quote>Originally posted by: Lacatahoula

It doesn't backfire. You can feel that the motor seems to stall as if it were idiling @ maybee 500 rpm then the idle comes back up to normal. If I'm not mistaken it drive by wire. There is something writen on the throttle saying something to the effect of to avoid stuck throttle that its electronicly controled?</end quote></div>


It isn't actually drive by wire,it uses a cable. The ETC is the black box on the right handle bar. It has a set of contacts that close when there is slack in the cable,when the contacts close it cuts ignition to the engine. It is a safety feature in case the thottle plate sticks open. The procedure for adjusting it is explained in the owner's manual,the adjuster is a few inches down the cable from the ETC box..
One quick way to tell if that is the problem is to keep light pressure on the thrumb lever when you let out,not enough to open the throttle plate,just enough to keep the cable tight.. Go closely check out the thrumb throttle operation,you will see the thumb throttle has a little free play,you can move it a small with little to no resistance at first then move it farther and you feel the throttle spring resistance...if you let out but hold a little,just enough to keep the slack out and it doesn't stumble then the cable adjustment is the problem..
Or you could just check the adjustment per the procedure..it's pretty simple to do..

 

Thanks for the replies. I'll check the manual this weekend and try adjusting the cable if needed.