I am new to the VFR and the VTEC, and need a little help from all the experts out here. I have also searched this and was unable to really find the answer. I bought a new 2004 and have put all of 980 miles on it so far. I'm getting used to the 4500 RPM stumble, but while accelerating to the VTEC engagement around 6700 RPM, I was expecting afterburners, but all that really seems to happen is a little more noise. While easing toward 7000 RPM, and holding that RPM it just seems to have a surging feeling like it is missing. No real feeling of increased power, up through about 7700 RPM. If I accelerate through this zone, I don't seem to experience it. I have to admit that having done my first twisties in the VTEC range, it did get a little sporty, feeling that I was on a bucking bronco with it surging in the corners bouncing around 7-7500 Thanks for the help
The VFR's throttle is pretty twitchy by most peoples' standards, and the stock FI fuel map is certainly on the lean side. What you're describing sounds pretty much normal, maybe a little more pronounced than most. If you don't want to spend the $$$ on a PCIII to remap the fuel curves, a TurboCity fuel pressure regulator will help smooth the ~4500rpm stumble and the 7000rpm surginess, though not as much as the PCIII with tuning. Might lose 1-2mpg on fuel economy, but it's an easy and fairly cheap install.
You've had this bike for 2 years and you only have 980 miles on it? Maybe it feels odd because you never ride the dang thing! Put some miles on it and get used to it.
ive had my vfr less than a week and ive found many of the same issues. the bike definetly has personality.
i havel all those same issues also. but its nothing i cant overcome with more seat time. i do plan on adding a pcIII but i planned on that prior to even finding these issues.
the vtec to me seems more prevalant when your harder on the throttle building rpms fast.if you just slowly roll into the vtec it mainly just makes noise,i agree. but if your hammering the throttle and wizzing threw the gears you can deffinetly feel it pull harder when it kicks in.
if your gonna be doing corners with high rpms stay above 7k rpms. but on mine the transition is rather smooth if im slowly adding rpms like i would in a corner.on exit im usually stable enough and do roll on hard and the vtec does kick but im not into the apex where it would matter.
VTECS are tuned for uber-low emissions. The 2002 VFR800 was built to meet or exceed the new California emissions standards that have not even taken effect yet. (2008 IIRC)
Witness: cat converter, 12 hole injectors, semi-closed loop FI system.
READ: they run lean.
You need to find a way to feed it more fuel. Then the bucking/surging will (mostly) go away. The bike will always feel 'digital' compared to carbs though.
Try a set of O2 eliminators, a Turbo City FPR or perhaps a PCIII or Techlusion box.
I've got the TC FPR, but on a 5th gen, no cat=no O2 sensors.
Bike definetly runs richer with the TC FPR Vs stock, I can smell it. No dyno time, no exhaust gas analysis, sorry.
If mine (o5) did all this I would unload it fast! Never had any of these issues on mine in 20,000km...just the touchy slow speed transition which I found lowering the gearing and a tighter throttle made good enough(not cured)...I have no lean surge anywhere, no missing, and it definately has a kick when the vtech hits..or the powerband and noise combo, whatever..but it jumps good at 7 g.
So whats the diff? I dunno..I do and have since the engine first got warm on the way home from dealer, driven the $%^&%^&$ outa it..Cant see that making any diff tho... smile.gif
But seriuosly you guys say this is normal? Thankfully I havnt found that..If i do, its gone...
One of the main design flaws of the vtech is that if it's not used on a regular basis the unused valves get carbon deposits on them. The fuel will not atomize correctly (fuel soak) The engine needs to be revved. Try giving the motor a good burn every so often. Then see how it is.
I think rjforlife just got his bike, not 2 years ago, but rather he bought an '04 leftover somewhere kinda recently.
+1 on Deathstar's info. VTEC doesn't seem very noticeable when you creep into its engagement point. But it does give a bit of a kick when you hit VTEC while accelerating hard. And that's one more reason I love it. Even if you do creep into VTEC range, I think you'll find that you have better throttle response and must quicker acceleration once you're in VTEC.
+1 on steve tech's post, too. Gotta run the bike hard once in awhile to keep those nasty deposits outta there. You have to periodically remind your VFR that it's a SPORT-touring bike, not the other way around. Viva la VTEC!
TimC, Oct 18 2006, 02:14 AM I think rjforlife just got his bike, not 2 years ago, but rather he bought an '04 leftover somewhere kinda recently.
+1 on Deathstar's info. VTEC doesn't seem very noticeable when you creep into its engagement point. But it does give a bit of a kick when you hit VTEC while accelerating hard. And that's one more reason I love it. Even if you do creep into VTEC range, I think you'll find that you have better throttle response and must quicker acceleration once you're in VTEC.
+1 on steve tech's post, too. Gotta run the bike hard once in awhile to keep those nasty deposits outta there. You have to periodically remind your VFR that it's a SPORT-touring bike, not the other way around. Viva la VTEC!
second that. if you creep into the vtec it gets a bit confused. ride it like you stole it and it will impress biggrin.gif
rjforlife, Oct 17 2006, 06:29 PM I am new to the VFR and the VTEC, and need a little help from all the experts out here. I have also searched this and was unable to really find the answer. I bought a new 2004 and have put all of 980 miles on it so far. I'm getting used to the 4500 RPM stumble, but while accelerating to the VTEC engagement around 6700 RPM, I was expecting afterburners, but all that really seems to happen is a little more noise. While easing toward 7000 RPM, and holding that RPM it just seems to have a surging feeling like it is missing. No real feeling of increased power, up through about 7700 RPM. If I accelerate through this zone, I don't seem to experience it. I have to admit that having done my first twisties in the VTEC range, it did get a little sporty, feeling that I was on a bucking bronco with it surging in the corners bouncing around 7-7500 Thanks for the help
It is an example of engineering genious (sic) combined with the pack of liars in the marketing department.
Read the list for a while before you start throwing money at it.
Putting more miles on it won't hurt either.
You will find words to searh on. Like turbo city, fuel pressure regulator, fpr, O2 sensor, eliminator, radio shack.
VTEC VTEC you get people that luv it & people that hate it but the fact is the VTEC is a outstanding bike straight off the show room floor.
I own one have read about every post on the subject & the 100's of fixes people tend to throw at it. There is one fix that doesn't cost the earth & I would put money on fixing nearly every problem or so called problem there suposed to have. REMOVE THE CAT & FIT 02 ELIMINATORS.
The cat is the cause of all the problems in my book & if you go to an exhaust place ask them to cut bottom out gut it then reweld cut section back on problem solved. The 02 eliminators just put the system into closed loop as the 02 sensors are really there because of the cat. To fit 02 eliminators just do search here & you will find a simple resistor mod that will cost you about 50cents.
The VTEC operation gets better with mileage on your bike & if you want more kick try using a high octain fuel.
Mine is an 04 & haven't guted cat yet but do have PC111/dyno map, aftermarket cans & 02 eliminator resistor mod & it kicks you in the pants.
I've got an 06 with 9000+ miles now on it...ridden almost daily. Getting so used to everything about it that I don't hardly notice V-TEC, flat spots, etc. anymore. JUST RIDE IT & ENJOY IT.......... fing02.gif beer.gif
also if the 980 miles you put on are the only miles on the bike that might be part of the problem also. i remember when i first got mine it was down right scarey...i would crack the throttle and nothing would happen for a second or two then bang! here comes power and it even died once when i pulled in the clutch but after about 1000 miles it was broke in and super smooth. No problems since...i also ride about every day that it doesnt rain so yea just ride the crap out of it and it will love you back lol.
At 980 miles the bike isn't broken in yet. Give it some miles before you try changing anything. I really don't think mine started to feel broken in until I had 5-6K miles on it.
Add me to the list of VTEC owners who say it takes a while to break in. A few thousand miles do a lot towards smoothing things out. The only performance mod I've done is hooking up O2 eliminators to get rid of the hunting/surging around 4-5k rpms and it runs great now. I spend a lot of time in that RPM range because I mostly commute. This morning when leaving a red light I moderately accelerated up through about 8k in second gear and felt not a kick or stumble at VTEC transition. This is after about 28k miles on the bike. I love this thing!
Just keep riding it. Both you and the bike will get better. beer.gif
The VTEC VFR like a fine wine, gets better with age and miles.
I had some issues for the first 2,000 miles or so. Orginally, my only mode was a K&N filter and at 17,000 miles I put a TFI box on (poormans PCIII, allows you to adjust the fuel input manually, but it does not alter the fuel map in the ECU). That helped alot, but my mile dropped by about 2-4 mpg. I ran the TRI for about 14,000 miles. 3 months ago, (at 33,000 miles) I turned off the TFI to get my mileage back. It has run flawlessly ever sense then. Not weird surging, no throttle issues, runs like a champ.
In a few more months, I may sell the TFI if I feel like I don't need it anymore.
Time and miles will smooth out some of those issues. I am glad I waited.
SilVFR, Oct 18 2006, 10:07 AM The VTEC VFR like a fine wine, gets better with age and miles.
+1.gif
Put some miles on it before you start spending a bunch of money! My 02 felt worse in the first few thousand miles, but like mentioned it's gotten better with each mile. fing02.gif I just turned over 42k miles of rippen twisties on it and I have No issues at all and it's stock other that Slip-Ons. tongue.gif
End of thread · 18 posts recoveredWayback Machine snapshot 19 Oct 2006