Poor running/stutter when trying to ride at low speed

[Broadband10]

Good Afternoon, I'm sure this subject has probably been covered somewhere before, but I have just bought my first big twin, K4 DL1000, and since I have had it, it has had a problem with holding a steady speed when riding in town traffic at low speed, it tends to be really lumpy, misfires, and really stutters, although when on motorways and dual carriageways at higher speeds 70mph+, it seems to be fine.

I know that switching from inline fours to a big twin is considerably different, and I expected it to be a little lumpy, but this is beyond what I expected, and finding it very difficult to enjoy riding it.

It has had the stock exhausts replaced with two aftermarket Delkavic cans, and I'm not sure if this may have contributed to the problem, would there have been a need for any remap?, I would be particularly happy if anyone can share any similar experiences, and even more interested in any solutions that they may have found.

regards
Andy

[Gassoon]

Hi Andy, first of all I don't have a 1000 (Vee) , but I understand they do run a bit lean and not so smooth as the 650 at low speeds/rpm
Some owners do go 'power commander' route to smooth things out.
But assuming it's more than the usual experience, your issues could be caused by a number of things, well summarised on the old VSRI forum HERE

It's also worth searching this forum using a phrase such as 'low speed running problem' , and similar..

[hookie]

The Vees are known to be lumpy and uneven at low speeds around town. Some are worse than others. The first step is to get the bike properly serviced either by a good garage or yourself if you can do it. If that doesn't improve things then there are a number of options. Some Suzuki dealers may still possess Yoshimura fuel injection tuning box which can be plugged and the fuelling adjusted to improve the running. They're getting bit old now so you may have problems locating one. My Vee was not too good when I first got it but was improved firstly by fitting a set of less restrictive (noisier!) exhausts and then a Timing Retard Eliminator (usually called a TRE which you can probably still pick up on Ebay for a few quid). In reality the TRE shouldn't have made any difference but if definitely did. The final thing was to fit a Power Commander. This was not really fitted to improve the running but to try and improve the fuel consumption as I always thought the bike was running rich which is contrary to what is generally thought. The end result was that the fuel consumption improved slightly but the low speed running improved as well. The bike will happily chug along in traffic at around 2000rpm without misfiring or poor throttle response. Getting a Power Commander can be pricey unless you pick up a used one and fit it yourself. I think I paid about £80 for mine. Another very worthwhile improvement for the Vee is to lower the gearing either by reducing the gearbox sprocket by one tooth or increasing the rear wheel sprocket by two teeth. Makes the bike noticeably livelier and improves the acceleration.

[Broadband10]

Thank you Gassoon and Hookie for your comments, I knew that when I bought it, it was going to be a little lumpy, I just didn't expect to be as bad as it has turned out to be! is it very difficult to fit a power commander, or expensive to get one fitted?

[hookie]

Fitting a PC is a little tricky as to do it properly you have to disconnect the Oxygen sensor and then unplug the related wire from the bike's engine management computer to stop an error message coming up on the dash. The difficulty was finding out which wire to disconnect as there is more than one wiring layout used on these bikes. But if you're happy with bike DIY it's not that hard. Ideally the way to get it done if you don't mind the cost would be to go to a PC/Dynojet specialist who knows this particular Suzuki model and then get it set up on a rolling road/dyno. I've no idea of the cost. I'd suggest contacting a couple of companies to see what they'd charge. I'd also suggest avoiding some of the "Tuning boxes" popping up on Ebay...

[Broadband10]

thanks Hookey

[pichulec]

I would start with TRE. I fitted to mine short while after buying the bike and bike is now rideable from anything over 2k rpm, before I had to keep it over 3 - 3,5k to stop being lumpy.

[wurzel]

Hi there, check, or have checked TPS, and throttle body balance, fit a Tre from healtech.
If you do lots of low speed riding think about the suggestions on gearing, and make sure your chain is not too loose.These will make improvements.
A power commander and setup would be my next step if not happy by now.
They are always a little jerky, I slip my clutch, often in a higher gear at just over tick over,after a while it becomes instinctive,but each to their own.
I have done all the above and more on my 2014 bike,in an attempt for power gains,and it has helped the low speed stumble.
The 2014 bikes were recalled for a new ECU,to negate this problem.
Good luck and keep us posted.

[Methusela]

Before you go down that road have you checked that it has had  the ECU upgrade done under recall ? Mine was just like that before the recall work was done. Not perfect after that, but much better.

[hookie]

Broadband10's bike is a K4, a 2004 model, well before ECU updates became available. Using a Yoshi box it is possible to re-program the existing ECU's fuelling a bit to improve things. A Power Commander effectively bypasses the on board ECU with it's own ECU and program which can be altered on the fly (preferably when on a rolling road/dyno) or by downloading a new one into it. Dynojet have a range of fuelling maps that can be downloaded and transferred into the PC on the bike. A starting point is to use a map that most nearly matches your own bike, I.e. exhaust system, air filter etc.

[Methusela]

Ah obviously I didn't pick that up sorry for the mislead.