intermitent surging?
 

Hey guys,

ive been tweeking my XTR since getting it and have fitted the Kev Mod, k&n filter, removed the snorkel and replaced the cush drive, but i am still getting a intermitent surging problem?

i can for the most part ride round it but it's bloody annoying, being well behaved 1 minute then surging the next, any thoughts on this guys?

Si

Welcome to XT world.....
you are never going to get rid of it 100%...
Try kevs throttle mod...

Petenz, already have it fitted, i'm curious how it went for a few days before returning as a intermitent problem, i'm figuring there is some variable at play here that is causing this.

Maybe air temp changing fueling rates...???

I did say you are never going to cure it 100%... is not quite true..
My XTR is surge free..or at least yer can no longer feel it..
I have a Rekluse centafugle clutch fitted... That seems absorb the surging from the motor at lower revs before it gets to the rear wheel...

I really never tryed to cure the surging... as i never use it around the city in slow traffic where the surging is most noteable... only used on the highways/
open road to get the the tracks/trail etc...And long distance ADV rides... is mostly highway riding...

I'm starting to wonder if the fualt is not the engine and is else where, i've only owned the bike a short while so there are alot of unknowns about it's past maintanence.

When you said about the air temp changing fueling rates! that confused me a little, i understand exactely what you mean but confused with regards to the kev mod being fitted, i thought once you'd found a sweet setting the air temp changes shouldn't cause problems to the setting you had dialed in or am i inderstanding it wrong?

Hi Simon, have you also raised the idleing speed or tickover at closed throttle to at least 1450-1550 rpm?

You will find that this simple fix might work wonders as often the tickover on these bikes is too low, and when you let go of the throttle the bike starve and causes it to surge. In some cases we've had to adjust also the TPS, throttle position sensor to the correct angle.

I would recommend that you join the XT Supporters http://www.xt660.com/showthread.php?t=1475

and Ask Kev in a provate message to give you a step by step guide on how to overcome all these little issue, I guarantee that he will be able to help you minimize the problem altogether.

Hi Captmoto, i've upped the idle to 1350ish, when i picked it up i found it was doing 11-12k i'll move it up further and see how i get on with that.

I don't know why but i think chain slap may be something to do with, but the chain is set to 50mm but i don't know it's history so i wouldn't rule out a dead link or 2, but none appear siezed when i've looked. and as per a previous post i've sorted the cush drives with new ones but may still try the mod to see if there is enough play within the new drives.

First and foremost all fuel injected engines surge the only way to limit it as much as pos is either an ECU map like a Rexxer or fit a PC and have it set up on an dyno,I had the Kev mod it's a good bang for buck but then went to a PC and it's a major leap forward not so much hp but more so with cutting down the likes of surging.

I'm keeping PC as a last resort, fingers crossed i can the results i want as cheap as possible. got a wedding to pay for next year.

There's 3 secondhand ones on ebay as we speak!!

how did i miss those :BangHead: you sir are a gent

whats a sensible price for a used PC, and is it the same model PC for 2004-2006 and 2007+

I'd be looking at �150 tops.

i'll keep a eye on these then, there's 1 still at �25 but a few days on that still so i think i'll watch that closely.

other than trial and error is there a way to dial in the kev mod, say for example have the rpm on the dash and adjust it that way?

ok i found a way to dial it in using the air temp on the diag system, been doing some playing and finally getting somewhere, surging is behaving a bit better but now finding when i come down from a few miles of 60mph and enter a 30mph zone it will surge for a while? i'm thinkin it may have something to do with the sensor getting chilled and taking it's time to correct for the warmer air at slower speeds, is this about righ and is there any fix for it?

With all fuel injected bikes the trick is to be either on or off the throttle the moment you start steady faffing about with the throttle they hunt even with a PC I can make my XT do it if I try.

It's like having tooth ache and you can't stop poking it!!

So thinking about it, you could get round it by playing with the sprocket ratios too?

Just a update really incase anyone has been following, i've had a busy few days working on the bike and all surging is almost completely gone.

unfortunately i've done a few things in 1 hit without any road tests, but i've moved the TPS down from 17 to 16, i've returned my CO back to standard, i've done the cush drive mod and then gone and had new tyres put on.