FZR250 1988 3HX Needle and Seat set Part number 1FN-14107-10-00, $111.14 US each plus shipping from Megazip Keyster Japan also make's a replacement needle and seat set for the 3HX's, and it's listed as fittting a few different model Yamaha's and Suzuki'S which give's you a few more option's https://www.ebay.com.au/itm/KYV-33L...264490606025?_trksid=p2385738.m4383.l4275.c10 Yamaha XVZ1300 Royal Star FJ1200 1988 Onwards > XV1100 Virago 1988-1999 FZR400 FZR1000 Genesis XV750 Virago 1988-1997 Suzuki VS1400 Intruder VS1800 Intruder XV800 VZ800 Marauder The other part number's the Keyster kit replace's are- Yamaha 1FN-14107-10 3EN-14107-10 1FN-14107-15 3CF-14107-15-00 Suzuki 13370-39A00 13370-38B00 IFN-14107-15-00 $26.29 US ea https://www.boats.net/product/yamaha/1FN-14107-15-00 3CF-14107-10-00 $16.31 US ea https://www.boats.net/product/yamaha/3CF-14107-10-00 The other needle and seat set's may have different diameter inlet diameter's but i have found that rarely make's a difference to the way it run's. They may fill the fuel bowl quicker if they have a bigger i/d, but it's not noticeable