[FIXED[ new member: surging issues [FIXED FOR REAL]

[roasty_duck]

I bought a 2001 vtr 1000 around 3 weeks ago, since buying it, its had a surging issue.. i thought it was over 3500rpm but it appears to be from the get go... bike seems to lurch back and forward when holding at a constant throttle but as soon as i open it up its fine.

when i got it..

k&n
190 mains
48 pilots
high rise carbon cans.

i changed to

standard mains (175?)
48 pilots left in as suggested by others.
standard filter.
standard exhausts.

its still surging.
carbs where cleaned thoroughly.

checked diaphragms, no holes, checked petcock diaphragm, no holes.
all breather pipes clear.
all vacuum pipes clear.

tps at 500 ohm
carbs balanced
clean fuel
pilot screw played with for hours on end
i suspected the plug caps where breaking down, the resistance was quite a bit out but switched 1 of them for a different cap closer to 5k ohms and it didnt solve it but im not sure these would be the issue.

been through a whole can of carb cleaner spraying it round the carbs to check for air leaks and i can't find any.

it does still have the pair system though once again im not sure this will be the issue as they wouldn't fit them if it would make it run this bad.

only non standard parts on the bike now are:
iridium plugs (previous owner fitted)
48 pilot jets.
high rise carbon exhausts (still surges with standard exhausts)

[Squiffythewombat]

Best of luck buddy, this one has us stumped guys - any input would be great?

* calls the firestorm gods *

[roasty_duck]

If anyone here diagnoses this i will lend them my partner for the evening! this has driven me mad almost every day for the past 3 weeks

[lloydie]

If your getting surging it's either because it's running lean or rich .
Few thing that comes to mind without test riding it is airflow .
Do you have the tray fitted under the carbs ?
Does it have a full fairing ?
The emulation tubes could also be worn out if it had Dyno jet needles fitted .

[roasty_duck]

full faired
standard needles where used when it was jetted it just had shims in it
it did seem to get better when i pulled the choke a little but not much better but i may have pulled it too much

[VTR Phoenix]

Agree with the rich/lean theory. Pull the plugs and check the condition. This will tell you black is rich white is lean.

[Wicky]

From the location in Kent - maybe TonyM or Mac can troubleshoot- possibly swapping a few known working bits&bobs around one at a time might help narrow the source of the problem, plus they have a good range of Honda special hammers...

[roasty_duck]

the rear plug was about the right colour, the front was a light black

im happy to ride out to someone local so they can try it out and see if they can work it out

[MacV2]

My F2 does it as well. It's had the pairs removed & even has F style cam covers to do away compleatly with the pairs gubbins. still get a bit of surging...as said it's on lower revs constant throttle...You ride round it....

[tony.mon]

I have a set of std downpipes with lambda sensors installed, with a display unit which gives you real time fuel/air mixture readouts as you ride.
That's the sort of thing you need, if you don't get it on a dyno.

Trouble is, by the time you've ridden it up to mine and faffed around fitting all that gubbins, sheared a head stud or two, drilled them out, etc, you might as well stick it on a dyno and get it diagnosed instantly.

Laguna Performance in Ashford is the best I know of in the patch.

[Squiffythewombat]

I have a set of std downpipes with lambda sensors installed, with a display unit which gives you real time fuel/air mixture readouts as you ride.
That's the sort of thing you need, if you don't get it on a dyno.

Trouble is, by the time you've ridden it up to mine and faffed around fitting all that gubbins, sheared a head stud or two, drilled them out, etc, you might as well stick it on a dyno and get it diagnosed instantly.

Laguna Performance in Ashford is the best I know of in the patch.

Hey Tony,

Got any pics of your cool setup then? Is this a DIY thing or purchased? Sounds very handy!

(ps - thanks for the gear lever, turns out clutch casing and few other bits were dead too so have bought a second as a donor!)

[tony.mon]

I have a set of std downpipes with lambda sensors installed, with a display unit which gives you real time fuel/air mixture readouts as you ride.
That's the sort of thing you need, if you don't get it on a dyno.

Trouble is, by the time you've ridden it up to mine and faffed around fitting all that gubbins, sheared a head stud or two, drilled them out, etc, you might as well stick it on a dyno and get it diagnosed instantly.

Laguna Performance in Ashford is the best I know of in the patch.

Hey Tony,

Got any pics of your cool setup then? Is this a DIY thing or purchased? Sounds very handy!

(ps - thanks for the gear lever, turns out clutch casing and few other bits were dead too so have bought a second as a donor!)

Definitely diy-



Click on the smaller pic for a video.
Worked very well, though. And up for sale if anyone fancies it!

[sirch345]

Blimey Squiffers where have you been hiding we haven't seen you for ages

Good to see you back though

Getting back to the O/P question. If you're not sure how many miles the iridium plugs have done it might be worth trying a new set, clutching at straws I know but for what it costs it might be worth a try.

Out of interest how many miles has the bike done

Chris.

[fabiostar]

get it on a dyno with a good operator, sounds weak if the choke helped it,


I claim my prize lol

[mwkeats]

Hi, did you check the slides to see if they had an extra lift hole drilled? Standard is just 2 lift holes plus the one the needle goes through