the secondary injectors come in at over 5500 RPM right or over 50 degrees of throttle opening So if that were causing the problem then surely it should occur then. When you give it WOT from a standstill does it bog down or cause any problems? Try holding at 6000 RPM and then give WOT see what happens?
Could it be a vacuum line problem?
Did you disassemble the airbox by any chance? There's a fair few breather hoses connected on that, also some vacuum lines under the MAP sensor near the airbox.
TBH I really have no idea about what could be causing this. Could your fuel pump filter be clogged?
That's basically what I was getting at. It bogs down when I reach a certain RPM (higher than 5.5k though) or when I whip the throttle open. So yes it happens exactly how you say.
I checked all the vacuum lines the first time this happened and I'm pretty confident they are ok.
I've never had the airbox off myself but the previous owner said it had a new filter installed. That was done by a shop but you can never entirely trust them. However the problem hasn't been constant since I got the bike so figure its something more variable than the hoses being off.
I am leaning towards the pump. From googling and looking at it, it seems the only filter is that orange gauze stuff on the bottom which I don't think would strain a whole lot out. Must be something internal but I can't see or get to that. I'm hoping that is clogged and the finer stuff hasn't made it through.
Take power commander off, or run a "zero map"?
see if that changes performance?
I've queried the power commander before but with finding this rust its hard to rule that out as being the problem. I mean surely the rust isn't sitting there having no effect at all and its the PC???? I do want to get it tuned again though so it will be getting checked out.
First off, as above, disconnect the power commander.
Then, the thing that I find concerning is the pump cleaning and fine rust powder. If that has gotten through the filter it may very well have blocked up your injectors. If the power commander makes no difference I'd be replacing the pump and getting the injectors tested.
As above. How exactly do I disconnect it? It seems relatively hardwired in but I've only seen the box in the 'boot' and haven't investigated where the wires run. Is there a simple plug in / plug off somewhere??
I'm really thinking its pump replacement time. Few hundred bucks on ebay. Will be searching about for my options. The tank appears clear of any rust forming so I have a feeling the rust is actually parts of the pump coming away. And I guess a new tank would only be up for rusting again as well.
It's also my daily at the moment so haven't had it apart again. It gets me to and from work no problems, can even open it up. Its only after I have been on it for a bit constantly (and I imagine its had time to suck up a heap of crap from the tank) that it starts giving me grief. And it gets worse and worse until I stop and give it a rest (and I imagine the crap works its way out of the pump a bit) and then it goes again for a bit.