K4 650s running rich - Dyno Graphs included

Hi all,

Newbie to the forums here. Forgive me if this is in the wrong place!

Wondering if I can get some help on some ongoing fueling issues I'm having with my K4 SV650s. I'll bullet the back story and then fill in on what's gone on recently. I've had a good search but couldn't find anything I thought could help. Sorry if I've missed something!

- Bought in Jan 2011, had engine trouble (misfires, 325 syndrome), swapped plugs, fixed.

- Year and a bit later, broke down on a journey. Misfires, sooty exhaust, black plugs. Discovered the fuel system was running way above pressure. Suspected the pressure release valve in the pump. Removed pump, dismantled, manipulated valve, re-fitted pump, no issues whatsoever (mpg fine too, though power surged a little)

---

- Current problem-
Was running fine before winter. Left it to sit sheltered over winter for a month, came to start it and wouldn't start with a fully charged battery. Turned over but wouldn't fire. Cylinders had flooded upon trying to start and spark plugs were horrible. Plugs were swapped, oil & air filter replaced, new oil (castrol) and coolant, fresh fuel and a bit of redex (you never know...!). Took it for a dyno run during my MOT which is the first -RED- run. Notice the fueling and how rich it's running. Bought a replacement fuel pump and fitted it. Seemed to be running better and more smoothly so took it for another run, the -BLUE- run. It's a bit better, but still really rich. The guy then compared it to a colleague's (2012) SV650 which is the -GREEN- run. The new SV's fueling is much better, but still rich which I find quite interesting.

Can anyone shed any light on what might be causing the rich fueling? Injectors? ECU? Other things? I'm pretty stumped at the moment and although my bike is running fine now, I'd rather ride around knowing I'm not going to break down again on the third lane of the M25!!!

TLDR:
- Red first run on old pump, running mega rich.
- Blue second run on new pump, still running rich.
- Green comparison run on newer SV (9k miles compared to my 31k).

Thanks in advance.

RAM

PS. Everything on my bike is stock - exhaust, etc. Only addition I've added is heated grips.

[Bibio]

the earlier K3-5 bikes do run a little rich compared to the newer models as from K7 onwards the bikes have twin spark heads.

it might be worth setting the TPS and balancing your throttle bodies.

[Bibio]

the earlier K3-5 bikes do run a little rich compared to the newer models as from K7 onwards the bikes have twin spark heads.

it might be worth setting the TPS and balancing your throttle bodies.

Hi Bibio,

Thanks for the response. I'll get on to doing the TPS this week and see if it's poorly set. Need to go get myself the right torx bit for it first and find myself a paperclip and some electrical tape.

Re the throttle body sync/balance, I've got a friend asking around to see if anyone's got one. Would rather do it myself if I can!

Is it normal to run 'that' rich though? Forgive me for my ignorance!

Hopefully get back to you soon. Just awaiting delivery of tools purchased. Tricky getting them delivered to my address due to living away from home as a student! Ah well. Here's to some tweaking next week! Sync first and then TPS right?

Also, I'll have a 4 gauge carb sync tool for people to borrow in the south east should anyone need to.

[Bibio]

wont matter which way you do it as each are independent in the over all.

Ok. Will get back to you after the stuff arrives and it's done! Thanks for the help so far.

[ophic]

I thought they were set to run a bit rich because it's safer than lean and because most folk fit aftermarket pipes, which flow better and therefore lean it out a bit.

Why is the red line so much smoother than the others in the lower graph?

The red line is the result from a run on the dyno a few days previous. As it's loaded data it's shown as smoother but I remember the results from it and it was wobbly like the other one when done, but even richer. It's interesting really just how much lower it is compared to where it should be. Power dropped too by 2bhp. I'm just trying to get it to run as smoothly as possible. I'll be sticking a Fuel exhaust on once I get the money.

[Bibio]

why would you think that its not running smoothly?