GSX250 cutting out at high speeds.

Update, I cleaned the carbs, changed sparkplugs, changed inline filter, cleaned tank, cleaned the petcock and cleaned the airbox.
It's turned out a little bit better.

 

Fun fact it was the engine all along. it just doesn't have the power anymore.

 

After I cleaned the carbies it smoothed out and stopped cutting out on me , instead it heavily struggles on hills and slopes requiring me to go extremely slow up them

 

Is it bogging down? It could be the fuel or a leak in the petcock, too much fuel getting through. Grasshopper had a bogging issue while running 95. It hauls arse on 91 though

 

It's not bogging unless I push it to 85-100km/h. the only other thing I have noticed is that exhaust fumes seem to be coming out from where the exhaust and muffler are connected together.

 

The exhaust also seems to have a white tinge to it.

 

That seems to indicate it's running lean at that rev range, I'm no expert through

 

Turns out they were just about sitting there, most of the bolts weren't even tightened.
any way it's running a bit better now still not a lot of top end power though.

 

Check the inlet rubbers or whatever parts connect the carby to the engine, could be sucking air through perish cracks in the inlet manifold or under the mating face seal/o ring or what ever it has.

 

Ok so I've found out that the problem was partly because I was not at a high enough rpm, since changing that it's been going a hell of a lot better yet it will still cut out if I push it really hard for a long amount of time.

 

Be careful not to blow the thing up, over revving on the stand without any load isn't good especially if she's got a bit of age, worn bearings, rings etc.
Were all still guessing, sounds like it could be low fuel in the bowls, check that the floats are set at the right height, there's been some improvement after you cleaned the carbies which suggests it could be them. I think you said you changed the fuel filter ?

 

I have replaced the fuel filter.