Hello

I don't post a lot on here, but thought I would share my experience with some minor 'tuning' of my GS.

Some background: I use this bike currently for rides with friends and family and by myself, not for commuting. I plan on keeping this bike several years because money will be low the next couple of years as I will be studying. This means selling the car and commuting to school on the GS hence putting alot of k's on it. Currently it has just shy of 19.000 km (11.800 mi) on it.

A few months ago I purchased a complete Blackwidow-exhausts-uk exhaust system for the bike. Very nice, decent quality for a low price. Included a 2-1 stainless steel headers and middle pipe section and a 270 mm (10.5 inch) end can. I threw the db-killer in some corner in the shed as that won't be needed, however the company also included a small piece of metal that I suspect is to limit flow ever-so-slightly, for backpressure reasons perhaps? Idk, but it's in my muffler now. Picture below:




I've been very satisfied with this purchase so far, and the bike has been running okay with the exhaust system as the only performance-affecting modification to the bike. Notice I wrote 'okay'? - At 5000-6000 rpm it lacked fuel and started to stutter when throttle was fully pinned. Same thing occurred as soon as I got above 8500 rpm.
Last week I finally did something about it, and drove it to a specialist here who focuses on tuning and optimizing of both carbed and FI'ed bikes, dude has even got a dyno and everything.
He kindly offered me to install a K&N filter in the stock airbox while he was underneath the fuel tank anyway, to which I gladly accepted. So a complete open aftermarket exhaust system and K&N air filter, is what I understand is commonly referred to as a 'Stage 2 kit'? Correct me if wrong

Anyway, onto some numbers:
My bike is said to have 47 bhp and 40 nm from factory

Once on the dyno, the bike put out 36.63 whp and 34,07 nm with everything stock, except the complete open aftermarket exhaust system
After some adjustment and the K&N-filter put in, it put out 41.11 whp and 36.63 nm. Reading dyno numbers on here made me feel satisfied with anything above 40 whp, so I find this result very satisfying.

The bike feels much smoother now, as expected. But most noticable is the acceleration in 3rd gear or above, at around 80 kph (50 mph) or above where it now seems to pull quite a lot harder than before without hesitating, which is very convenient in overtaking situations.

Dyno sheet can be seen below:
Red: after
Blue: before

The shadowed out lines in the 'background' is the torque curve.
The reason for all the jitter is due to a very worn chain. Has been replaced since



The bike has not been rejetted, this is purely with adjustment.

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Thanks for reading, just for the heck of it, here's a picture of the bike as it currently is:




List of other mods:
LED rear indicators
Flush-mount front fairing indicators
White LED bulbs behind dials in instrument cluster
Fender-rectomy
LED bulb in parking light
Tinted rear light (not shown on picture)
Osram Coolblue Ultimate 5000k headlight bulb

What jets did the tuner put in?