Motorcycle Repair: Problem Starting My bike, kawasaki ninja zx6, air filter element

Question
Hi,

I have a 1999 Kawasaki Ninja Zx6-r. The first problem I was having, was the fact that it wouldn't start when it was hot. I was advised to change the battery, so I did, it would still happen. The other day I was heading home after about an hour ride and the engine slowly starting decreasing rpm until the throttle was useless and it finally died. I pushed it back to my storage space. The next day I started it and it idled ok but wasn't very stable in the higher rpms 5000+. So I shut it down and put it away. The other day I went to start it, but it just cranks, it will not start. Any help or suggestions would be much appreciated.

Answer
Hi Brody!!

Ok... I'm kinda at a loss to understand why you were told to replace the battery to fix the hot starting problem, but perhaps there were extenuating circumstances I am not aware of. At least we know ya got a good battery now!! When the bike started to slowly die, it wasn't overheating was it? The temp gauage was under the hot limit right? If so, my gut reaction is that you may have a bad fuel pump or fuel pump relay. But if the bike was brought into my shop with a description you just wrote, I would first check for spark. I would remove the tank, remove the air filter element, spray starting fluid in the carbs, open the throttle at least half way and start it. If it starts, ya got spark. The next thing I would do is to check the flow rate volume of the fuel pump. Fuel pumps are sometimes prone to failure thru heat related causes. A failing fuel pump could easily cause the slow death you experienced followed by failure to start. The fact that it started the next day could be due to the fact that the fuel pump had cooled down, allowing it to pump at a weakened rate, hence the fact that it started to become unstable at 5000 rpms (when the amount of needed fuel is higher).

Now if there is no spark... this is a whole different ballgame. But lets go with my gut feeling and check those things out first... if ya don't have spark, then get back with me and I'll guide you thru those steps.... Good luck Brody and hang in there, it's usually something simple!!!

Jack