View Full Version : carby problems zxr 750

15th January 2006, 14:43
My ZXR 750 H1 is running poorly at low revs. I brought it a couple of months back and it was a quite boggy at low revs but 5000km later its getting worse. Its not a big deal for me because I don't ride in town much however I have to slip the clutch at anything under 25 kays and sometimes stalls when I open the throttle off idle. Its got an aftermarket pipe which could be part of the trouble if it wasn't tuned for it. It goes fine at mid and high revs though doesn't seem to keep up with the other 750's of its era. Anyway I don't want to spend too much money on it (didn't cost me much). What would getting it dyno tuned cost and would this likely solve the problems. What if I just stripped the carb down and cleaned all components and blastedthe jets with an air gun.

15th January 2006, 15:24
if its happening in the rev range between idle & 4000rpm its your pilot jets,or pilot air passage.
most likely their partially blocked, give the carbs a strip & clean.
or the carbs are out of sync, get them balanced

otherwise its either the carbs are leaking or the timing advance isn't working properly

15th January 2006, 16:34
What if I just stripped the carb down and cleaned all components and blastedthe jets with an air gun.That's a start, but clean it with chemicals to remove the petrol crap. As TWR says, it could be the little air passages and idle jets that are blocked. You probably won't be able to clean those bits with compressed air. And is your airfilter looking a bit sad? The difference clean, well setup carbs and new airfilter makes will make make you smile. You mentioned an aftermarket exhaust, at my extremely limited experience (Changed an end can, fitted a carb kit) yes, you need to fiddle with the carbs to make fix up what the exhaust has messed with. And when I changed the can, it was the lower end of the rev-range that got hurt until I sorted the carbs out and then it was fine again.

2.5 days.. 2.5 days..