This has got me a bit puzzled. I bought a Keyster carb rebuild kit for my ‘93 900ss and the jet sizes are markedly different from what are in it. The screw in main jet in the kit is a 70 compared to the 140 that’s in the bike and the new needles are massive. There’s more than one way to skin a cat when it comes to jetting, so it may be that the guys at Keyster have come up with a better set up that Ducati did, or it could just be the wrong kit. But multiple suppliers all list the same Keyster part number and jet sizes as being for a ‘93 ss. Has anyone ever seen this before and if so, what did you do? I guess I might just have to fit everything and try it.
Jets are just brass screws with holes in them. Each to their own but as far as I am concerned it doesn’t really matter whether they were made by Mikuni, Rolex or your uncle Bob in his garden shed so long as the holes are the right size and in the right place. Just for completeness in case anyone asks about Keyster kits in the future, I fitted the kit and it seems good to me. The bike now runs better than it ever has. Gone is the mid range rich flat spot, it doesn’t hunt at low revs, doesn’t foul plugs and it’s even nice in town. A vast improvement.
Whilst jets are just brass with a hole, quality jets are flow checked. Hence they cost what they cost. I'm happy it works for you.
