Hey there, Im new to this forum but not new to motorcycling. I just bought a 1995 Ninja 250 for my fiancee to learn on. I got it for a steal but it has some minor issues. First off, the bike will not idle down low at 1500 rpm. It will rev up fine though past 2-3k rpm. Sometimes it will idle on its own at 3-4k rpm but other times it won't. There is fresh fuel in the tank and I have already been through the carbs and everything appeared to be fine. The spark plugs and air filter are fresh as well. It seems like a vacume leak or something like that but I see nothing out of the ordinary. The other problem is that the bike did not want to run that great past 70 mph. It seemed like it was bogging and taking too much fuel and it took a long time to get to 80 mph. Can anyone help point me in the right direction? Any suggestions is greatly appreciated

 

Welcome to the forums. Since you went thru the carbs, how is the choke cable and adjustment?

 

Does the bike blow out dark smoke? i.e. running rich.

 

The choke seems fine (at least it does'nt feel like there is too much slack nor does it feel tight when I pull the cable). Also, there is no smoke comming out while idling but I never looked behind me when I was riding it down the road. It doesnt really smell like it is too rich. Could it be a mis adjustment in the valves? Right now, I am more concerned on getting it to idle more so than bogging at higher speeds so I can teach my girl to ride before it gets too cold.

 

The 250's have an idle adjustment ****? mark?

 

I just thought of something else...the previous owner used bolts that were too long to bolt the upper fairing to the tank which then punctured the tank on both sides, thus leaking fuel. Would the fact that the tank has holes in it cause it to loose any vaccume or pressure and cause the bike not to run right? I know the tank has a vent up by the gas cap but wondered it more "vents" or puncture wounds in the tank would affect anything. Any suggestions?

 

No matter where I adjust the idle screw, the bike either idles too high or so low that it dies. Ive tried the whole spectrum in the idle adjustment **** but still can't get it to idle.

 

Good point. But this ride is vacuum operated, ie carbs and not FI. More air pressure on top of the fuel I am not seeing an issue at the moment.

 

I just noticed that the previous owner has 8.8mm spark plug wires. These seem way too large. Could too big of a plug wire cause issues?

 

this is somethign that would worry me tons...