i have a 1998 zr 600 carb that runs but when you punch it, it starts to back fire, but if you hold constant throttle it runs fine. can anyone tell me whats wrong? i would really appreciate it. thanks Jay

Carbs out of sync. Same thing with the 00 ZL440 I had, and the carbs were out of sync. 5 or less minute job at a dealer, easy.

can i do it myself?

Have a service manual? If you do, with a little experiance, you proabably could, but for the price and speed of service, I'd much rather bring it to a good dealer. :beerchug:

how much would it be? roughly

I think my sevice manual was 25 on FleaBay (eBay). Your dealer should be able to get one for you. If not, PM me, I mght have a place you could find one at (~$30). :div20:

thanks a lot ill let ya know what the outcome is

dude how did it come out? i'm having a very similar prob with my 600 EFI.

http://www.hardcoresledder.com/forums/inde...howtopic=180927

Don't mean to jump into this late but he said it was backfiring. This is rarely a carburation problem because it occurs when fuel is present but spark isn't. When the spark does hit ,because of the extra fuel load, it backfires. This is true for 2 strokes and 4 strokes, car or sled. I've had this happen on a variety of cats and it was always the throttle bushing or the kill switch(especially if the button is broke off the kill switch which allows moisture to get into it).If you can push the throttle up or down while accelerating and it doesn't happen it's the bushing, if not unplug sensors as shown and you should be able to narrow it down. Hope this helps.

My buddy had a problem like this with his 98 zr 600 efi and it turned out to be a bad throttle position sensor.

just fixed mine.. it was the TPS.

TPS makes it do that if the spacers are bad, seen it tons of times......