Suzuki Bandit power loss?

[bonteli]

Hey guys i'm experiencing a loss in power on my 1995 Suzuki Bandit (GSF250) GJ77A with 52xxx kms on it. I'm really only having the issue above 90ish km/hr. It's extremely bad on uphills even minor-ish ones on motorways/highways. I come down a slope going around 150km/hr and start an incline of say 8-10 degrees (the whole time at constant maxed out throttle) and revs experience a constant drop and i just cannot get enough power so slows me right down to about 90-95km/hr. I've previously done the same incline with ease travelling between 130-140km/hr. I also notice the loss of power on a flat when i'm maxing out the throttle however it's sluggish with intermittent power surges although i eventually get some pull unlike on an incline. Also experiencing the very occasional power surges in short bursts at high speed at a steady throttle resulting in a jerky uncomfortable dangerous ride. Anyone have an idea whats going on and in what order i should begin checking condition/replacing parts?

No performance mods. My tach/odo have been dead for a while so can't give exact revs/speed

I bought the bike at 42xxx. Replaced my chain 2 weeks before noticing this power loss (i was told the sprockets still looked reasonably good by a mechanic so didn't do them). LBS had a quick look and suggested that chain isn't the issue and recommended a service to figure it out. Being a student, I don't have the finance to get a service and i would rather learn the condition of my bike by working on it myself so hopefully someone here can help. Aiming to check my spark plugs tomorrow and will update on its condition

[hayd3n]

why so fast rossi??

[haydes55]

Fuel starving? Drain the tank, try get the fuel filter out and replace it. Is there anything bouncing around in the tank?

Otherwise carbies will need a clean. And look at replacing old worn out components. This will be a big job.

[sinfull]

air intake dirty ! Start with the simple , ie: what ya said about plugs then air !

[the oldstuff]

air intake dirty ! Start with the simple , ie: what ya said about plugs then air !

Throw new plugs in anyway. Plugs can appear fine with a healthy looking spark, but can break down under load.
90% of problems are electrical so check all connections/earths are clean and tight (mmm..) and coils, leads etc are not leaking.
You can check in the dark for HT circuit leaks by placing on centrestand, run engine in top gear with back brake to put load on engine. Look for any spark leaks.

[the oldstuff]

Oops I quoted a post by mistake, clicked wrong tab what a doofa

[Locker15]

I got some work for ya for a whisky or two, losing power when applying full throttle, can ya help.

[Banditbandit]

I got some work for ya for a whisky or two, losing power when applying full throttle, can ya help.

Check out the carbs - could be flooding when you open the throttle fully - needle valve problems ... worn seats

What colour are your plugs? If black, then it's running rich (see above)

Replace the plugs .. full load can affect old plugs ..

[Blackbird]

+1 as per haydes55. Years ago, I had a BMW that progressively lost power at larger throttle openings. Without going into detail, it was the in-line fuel filter which progressively blocked around the outlet when sediment got stirred up.