Hi peoples, got an old 93 yzf 750, she breaks down @ 4000 rpm, sometimes it will spit an sutter till she breaks free, and off she goes, taken out the exup cleaned greased, no differnce, cleaned carbies, no differnce, fuel pump, seems ok, starts, idles, and once through, (if it breaks through) breaking down stage, it actually goes ok. 37.000 klms on the clock, presume to be actual, so up for major service, so is it timing, valves throttle senser?? what ever they do, battery, seems fine never hurd of charging causing this

When in nutural it will some times rev its tits off at first then will go into breakdown at the 4grand mark, so sounds like fuel BUT????? Help! sad.gif

forgetting the revving itself silly sometimes (could be a totally different issue) it might be then coil packs that are breaking down, although I'd expect it to happen under load throughout the rev range, but more noticably at a certain rev's.