fzr1000 running problems plz help me

[cornishghostrider]

hi i recently got a fzr1000 exup 1992 and i have running problems when i first got it it woul go fine then cut down to 4000 rpm and not go over blutter and and not rev anymore and i cleaned carbs new pipes and filters new airfilter and it sorted it but now have another problem it runs fine over 3000rpm but under it lumpy got no go and backfires sometimes cuts out dos not idle very well i spent days on it and dont know what it is and the exup valve seems to be working i loseing faith and really need help plz

[dan83590]

Sounds like your EXUP valve is stuck open matey. It'll go pop fart backfire pop pop pop fart and 3000rpm go go go.

Take off the tank and start the bike. Turn the throttle and the EXUP servo motor should turn smoothly as the revs rise. If that is okay do the same check at the exhaust valve, it should be turning smoothly too. After this check the cables are adjusted correctly. On the exhaust valve are two prongs and a hole, when the ignition is turned on (engine off) these should turn and line up.

If all this checks out then look at the carbs. Specifically the needles and Emulsion tubes, they should show no signs of wear at all.

[sweekster]

The symptoms described do point to the exup valve. So I'd second the suggestion of checking it and making sure it's working.

[smithy]

i have the same kind of problem i was hopeing someone could tell me where the fork on the exup valve on a 1989 fzr1000 is supposed to return to when the bike is ticking over after i have adjusted the cables mine and it drops back half an inch below where the pin goes in to lock the fork when adjusting is this correct?.Thanks

[dan83590]

The fork should line up with the hole with the ignition on, you can also run with it advanced slightly. Aparently gives slightly better power. Mine is level with the hole.