Poor runing at high speed - Suzuki Bandit 600

[birbal]

Hi everyone!

First of all I would like to mention that my mechanical skills and knowledge are not so great. I’m specialized in electronics.
So the problem is Suzuki GSF 600S Bandit 2001 K2. At the end of August 2011 I have changed the entire exhaust system (I don’t know if is relevant to my problem): new downpipes, new link pipe and new Beowulf silencer. After this operation I could feel the difference, in speed, power and of course different sound.
About three weeks ago it started to lose power at high speed (above 40-50 mph) and also there is a weird sound but I can’t figure where it came from and also I don’t know if I can describe it (maybe I will try to make a video in a few days, if I can record the difference). The thing is that when I start the bike in the morning, everything is absolutely fine...no weird sound, no difference in power. After about 3-4 miles of riding it starting to lose power if I keep it over 40mph, over 5-6k and the sounds appear. I mean I’m still able to drive it but is not normal...it doesn’t have that ‘thrill’ anymore.
What I’ve done so far:
- Check and clean the air filter
- Check and clean the spark plugs that are in very good condition
- Tight all the bolts on downpipes
- Check the oil level
The problem is still there and I don’t understand when the engine is cold, everything is perfect...after 2-3 miles, is not so great.
Does anyone have any idea?
Thanks!

[Bezzer]

Is the exhaust the only thing "non standard" , have you changed the air filter as well to a K&N or whatever also ??.
A Bandit is usually OK and copes with either an aftermarket can or air filter but will be a bit lean if both are done, a freer flowing set of downpipes.link and endcan can be a bit much as well .
Leanish running usually sounds and feels "crisper" at first then you can suffer a bit with it running too hot, if it's way too lean you'll damage valves etc.
Have a look at your plugs again to check their condition which should give you a pointer, with you changing the whole exhaust system may have been too much and it needs rejetting. A dyno run would let you know for sure.

If you're happy with fuelling then it could be on the electrical side, HT leads,caps,coils etc breaking down when everything gets hotter.
____________________
I used to be indecisive but now I'm not quite so sure.

[birbal]

[temeluchus]

Poor running when the machine warms up usually means you are running rich.

Often caused by one or more of the following:
Blocked air filter
incorrect float height
dirty float needle/seat
worn float needle/seat
worn emulsion tube
faulty float

one of these is a likely culprit.
____________________
Some shite cruiser. Now with guns and FREEDOM!

[Bezzer]

[birbal]

[Bezzer]

Nice one , at least you aren't damaging it as such running rich, weird though full exhaust and a K&N should allow a fair bit more air in, most have to rejet to if they do that. K&N isn't overoiled is it??.
____________________
I used to be indecisive but now I'm not quite so sure.

[temeluchus]

Its probably shit in the float valve or a worn out needle.
____________________
Some shite cruiser. Now with guns and FREEDOM!