okay folks here is a weird problem i am having with my recently bought 1995 ninja zx 600r with 14,000 miles on it .the bike runs like a dream but everytime that i start to ride the bike from a cold start, it seems as soon as i go 25 miles or so my motor acts like it is running out of gas. the tack will go to zero and back to the proper setting then back and forth,but the bike will still keep running but acting like it is running out of fuel ..slow stutter.. slow stutter you know the drill.... but after about 2 miles of this happining the bike return to normal and will run like a champ all day long. also sometimes after i go on a long trip if i let it sit say 5 minuites it will be hard to start so i choke it and it will start right up and run fine. soo people.. any ideals what is causing this problem ? or do i have a ghost in my bike that is playing games with me?

 

sounds like a fuel problem to me, check the lines, the pumps, the carbs, the jets, see if they are clogged. would you say its surging? could be a spark problem, not getting spark on all cyclinders etc.. its definitely fuel or spark, check both.

 

but why would it do it at almost the same time then clear up and run fine all day without happining again?

 

im really not sure, but in diagnosing an engine you want to check for 4 main things, compression, spark, oil, and fuel. checking the oil would be like a hard shifting problem or grinding noises or not going into gear you would want to look for metal shavings in the oil for example.. loss of power or other problems might be compression, (or pressure) in the cylinder or crankcase or bad seals etc.. spark would also be loss of power, surging, kinda like what you are saying, backfiring, misfiring, surges in power, spits and sputters, hesitation.. loose or worn out electrical wiring, bad plugs, clogged fuel passages, fuel restrictions etc.. its process of elimination, and i would start with fuel and spark personally in regards to your description of what its doing.

 

Yup, I would have to agree Fury... Coil starting to go out maybe. Carb loading up causing a plug to run rich/lean ??

Easiest and most common place to start would be fuel/ spark.

 

yep, spark checker, compression guage, and a hammer to fix the carburetors just kidding about the hammer... a fluke meter is always nice if you have a shop manual, you measure resistance (ohms) in an electrical component, if its out of spec, chuck it and replace it.

 

I have seen this on a bike before an it was the ignition coils. They sit right above the engine on the frame. When they crack and age the heat gets to them and makes them act wierd, then your fan kicks on and cools off the engine and coils and they go back to normal.

Does it happen more often in traffic and slow moving areas?
Try testing the coils, with the bike warm.

 

Is it just your tach going to zero or does the entire cluster die out for a split second?

Oh the joys I had on my 2000 ZX-6R when I had an electrical problem on that thing LOL... With your bike having such a strict pattern I doubt it would have anything to do with that but just another aspect to throw into the frey.

But fuel delivery and ignition system sound to be a likely suspect. Where in those departments of course is a fun one.

 

well i start the bike and let it warm up then drive about 25 miles at different speeds it happens at 10mph or 70mph it don't make a difference. maybe i will change the coil as described it sounds like what is happining the bike stills runs but it fels like your running out of gas. but it still maintains the speed and the tack goes to zero then back up then to zero back and forth then it will have a power searge and maintain normal operations. it seems to happen about the same time after the fans kicks in .

 

Have you checked your battery terminals to make sure they're clean & tight? Check your grounds also; on the frame, engine & wire harness. If not, then there's Probably water in the gas. Get some HEET & RXP and run it through. The added Ethanol in the fuels are causing a lot of problems like this. Other members have had similar problems due to water in the gas.