99 yzf engine poping carb settings?

4 replies to this topic
  • dealer

Posted April 10, 2006 - 07:14 PM


Just got my 99 yzf running again. Had the carb cleaned drained and refilled the gas. The only problem is I am getting a poping out of the exhaust almost like a moisture poping. I am thinking the carb settings are wrong. I also noticed the cooling system is very hot to touch and the overflow keeps on leaking coolant. It is giving me an idea that the cooling system is boiling over. The radiators are very hot to touch. The coolant is flowing so I know the water pump is working. Is their a thermostat on these bikes. I am hoping it is not the head gasket. Any sugesstions?

  • DRH

Posted April 11, 2006 - 01:20 PM


Where is the popping? During the rev or when you back off? How long are you allowing the bike to idle? They do have a tendency to boil over if allowed to idle for any length of time. If the bike is back firing (on decel) It usually suggest a lean condition. But before you start tearing into the carb again, do the simple checks first. Make sure there are no exhaust leaks, especially at the header pipe where it meets the muffler. Also make sure you have a new gasket in where the header pipes mounts into the head. If you are running an exhaust system where the need for a fiber gasget is needed at the Muffler and head pipe clamping area, I stronlgly suggest a new gasket there. This is where all my problems were found. I removed the carb so many times it was starting to give me nightmares. I was so sure that I had no exhaust leaks, but as a final straw and on a hunch, I unbolted the muffler from the two frame mounting points and was miffed when I discovered I still could slip the muffler off without undoing the clamp which I was sure was torqued down. I replaced both the gasgets and all backfires stopped immediately. If only I would have done this simple check first, instead of playing doctor with my carb. For now on its the three basic steps for me , spark, fuel and air leaks...

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  • Zique

Posted April 11, 2006 - 02:27 PM


I agree with checking for the simple things first. If none of those are the case, your jetting may be off now. Did you take it all apart when you cleaned it?

  • dealer

Posted April 12, 2006 - 05:44 PM


I had the carb cleaned not sure if they knew what they were doing. When you get on the throttle real hard it pops as it revs down. I will go thru the exhaust system then next thing will be to check the carb. What would be the standard settings for the carb?

  • One Louder

Posted April 12, 2006 - 09:25 PM


A little popping is normal for this bike

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