2007 VRF800 Stutter/rough idle at throttle

Hello all...

I just bought an 07 VRF800 with 3k+ miles so she's still rather new. I don't have much experience with motorcycle engines let alone VTEC one. Anyways, when I accelerate it seems she's running rough? The sort of feel you get from an engine that's not hitting all cylinders. The owner told me he hasn't written her in a while & has been garaged. When I mention the stutter of the engine he got on it an bolted from corner to corner at mach speed. The bike does take off and responds quick to the throttle but I still feel as if perhaps there's either bad fuel or a miss-spark? He mention that the bike has always ran like that when he got it at 1k miles. He told me that this bike has a close-ratio transmission but then again he was shifting at 4000 rpms & told me not to run it lower than 3rd on less than 30mph?? The bike still under warranty for another 8 months.

So are Honda VTEC VRF's run this way? I know since I really don't have a feel for this bike, I ran it slow at higher gears & therefore created hesitation. Yet, when I downshifted to 3rd around 33mph I felt lots of vibration from the engine through the fairings. Bringing it to 2nd at about 30mph still produced the same stutter, what gives???

 

Hi xlux, I owned a 2001 VFR and now a 2006 VFR and the nature of the idle is the same for both versions. So my comment is that the VTEC has nothing to do with the idle. Actually my 2001 had a lot more stutter than my 2006 does.
The irregularity of the idle is the nature of this V4. You can search out why on the internet. There are actually some good explanations for it related to the ignition timing.
With low miles and maybe sitting for quite a while you could try a fuel system cleaner (like SeaFoam) and see if that helps. My imagination told me it made a difference in the 2001.
If the bike has sat over the winter, running a few tanks of gas thru the bike will help. The winter blend gas around me is not very good and both my bikes run better after several fill ups.

Mark

 

Run a few tanks of gas, Don't ride below 3000 rpm in any gear! Use some fuel sytem cleaner as Mark919 said and check back with us later!

 

What everyone else said... Run some tanks thru her, run some seafoam thru her and keep the revs above 3k or 4k rpm.

 

:welcome: to the nuts house
As mention above flush the gas and run couple of tank with fresh gas and report back.
Might want to update your profile with location so we can help you better.

 

Without specific details, I would guess you were running the engine at too low RPM as others have suggested. This engine CAN be run down to 2500 RPM in 1st or 2nd gear, AT PART THROTTLE, if the PAIR valve is blocked/removed, but it's not particularly happy to do so. Above 3000 is when it is smoothest. The firing order that gives this engine it's unique exhaust note is the same that makes it rough at low RPMs.

As suggested, run several tanks of 87 octane gas through her with a good fuel additive (Seafoam, Stabil, etc.) to counter the debilitory effects of ethanol in the gasoline & report back.

 

Thank so much guys!!! I appreciate all advice & I will try running several tanks with good additive. I live in South Florida & this bike was brought from the West Coast of Florida & kept in a garage for extended period of time in super humid Florida. I will definitely need to replace just about every other fluid & start fresh because everything is stock from the dealer including tires.