My FZR600 won't start. No mods, all stock. I got it a month ago and it had been stored over the winter with no stabilizer. It wouldn't run, so I cleaned out the tank, made sure the fuel lines were clear, replaced the 3 bad plugs and it ran like a beauty. After about 2 weeks it slowly started to lose power, it was down to about 50% and had trouble starting. It was like when I was pulling the throttle it wasn't getting enough gas. So I went in and took the carbs out and cleaned them, the jets, everything. Put them back on and now it won't start at all. Checked the plugs, they are fouled but I can't tell if it's oil or just carbon. Cleaned them off and kept trying to start it. Took off tail pipe, nothing blocking that, there's a small amount of exhaust coming out when cranking. I messed with the air/fuel mixture screws. After that it started backfiring through the carbs, only one tho. Changing the air fuel screws just resulted in a different carb backfire. I took off the coils and tested them separately, they are fine. All plugs are firing. When cranking all carbs show fuel squirting out. The only thing I can't check is compression and timing. Are these the problems? If so, why was it running before hand so well? I don't think iv'e done anything to alter the timing. Is there a test to see if plugs are carbon or oil fouled? If oil then what? If carbon then what? Gas tank is full, carbs are clean. What the hell is going on?!?!?!

It is possible that th eplugs might be fouled but it seems unlikely after only two weeks running-my fzr would foul plugs but it usually takes months not weeks-also the engine would start but run on2 or 3 cyls. I found using one heat range hotter than standard plugs helped,esp. around town you seem to have been fairly methodical on your troubleshooting-if you have fuel and spark the next thing to check is comp. -if the plugs are wet it is likely fuel not oil-when I first bought mine it had sat over winter and would not start -it turned out that the valve clearances had closed up enough that it was low on comp. when ridden frequently it was ok but as soon as the oil had drained off the cyl walls it would not start-squirting oil in the cyls. would get it started but I pulled the cams and set valves to solve problem-starts ok now but I don't use the choke-you could lift the cover and check your valve clearances -it would be a good idea on a bike that you just bought-don't give up -be methodical and check one thing at a time-when you get it going it will be worht it

These things are really temperamental.The plugs are fouled again..I had the same bike and went through the same thing..It doesnt take much to foul them..Get some new plugs and she'll run like a beaut..Just remember not to choke it to much..Thats where the plug fouling happens the most..Always keep a spare with you and you'l always be on the good..It will work!!Have a great night!!!!!!!!

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