2004 250 ninja help -- won't start

[SON1C]

my buddy has a 2004 ninja 250 and it won't start -- he says battery is good, has drained fuel, change oil, spark plugs, cleaned and re jetted carbs, etc

We're stumped, what is the issue with this thing? It ran when he got it but was idling at 4k? (idle adjust valve didn't do much) then it stopped running and the trouble shooting began

[csmith12]

The 3 biggin's... gas, air, spark. Where do you stand currently?

[SON1C]

Originally Posted by csmith12

The 3 biggin's... gas, air, spark. Where do you stand currently?

i'm not sure what you're asking, fuel was drained and refueled, new spark, air should be fine?

[csmith12]

Sorry, I am from the old school.

In KY, even if you put a new plug in, we still take the plug out, while still in the boot, we ground it out against the casing, turn it over and visually check for spark and ensure it gets wet from gas. Yea, air is simple (aside of vacuum), clean airbox and filter that is not clogged. If you have those 3 things, it should run in some form.

[SON1C]

Originally Posted by csmith12

Sorry, I am from the old school.

In KY, even if you put a new plug in, we still take the plug out, while still in the boot, we ground it out against the casing, turn it over and visually check for spark and ensure it gets wet from gas. Yea, air is simple (aside of vacuum), clean airbox and filter that is not clogged. If you have those 3 things, it should run in some form.

carb was messed with by po, he thinks it's something to do with the valves now?

just really lost on this one lol..

[jkv45]

If it ran, but idled at 4000, I'd start by looking at the carbs to make sure they are seated properly in the boots. If everything else is correct, a high idle or slowly dropping RPM usually points to a vacuum leak.

The next thing for me would be the carbs. Plenty of people have "cleaned" the carbs, but haven't done everything necessary to remove all of the deposits. Why did he rejet? I'd put the (cleaned) stock jets back in for now. Were the idle mixture screw covers removed? They should have been. Set them to 2 1/2 turns out. The carbs should be synced also. Try opening the throttle slightly when cranking, especially if you have been on full choke. Also try reducing the amount of choke.

Others have added "new" gas that wasn't really that new...

Check that the battery is fully charged at 12.6V. If you've done some cranking without charging it most likely will be lower. If the battery isn't that great it will give you problems also.

I would give a good shot of staring fluid into the carbs while cranking to see if you get a sputter and pop, which would lead you to a fuel delivery issue.

Looking at the plugs is also a good idea. Are they black or tan? Are they wet after cranking?

[SON1C]

Originally Posted by jkv45

If it ran, but idled at 4000, I'd start by looking at the carbs to make sure they are seated properly in the boots. If everything else is correct, a high idle or slowly dropping RPM usually points to a vacuum leak.

The next thing for me would be the carbs. Plenty of people have "cleaned" the carbs, but haven't done everything necessary to remove all of the deposits. Why did he rejet? I'd put the (cleaned) stock jets back in for now. Were the idle mixture screw covers removed? They should have been. Set them to 2 1/2 turns out. The carbs should be synced also. Try opening the throttle slightly when cranking, especially if you have been on full choke. Also try reducing the amount of choke.

Others have added "new" gas that wasn't really that new...

Check that the battery is fully charged at 12.6V. If you've done some cranking without charging it most likely will be lower. If the battery isn't that great it will give you problems also.

I would give a good shot of staring fluid into the carbs while cranking to see if you get a sputter and pop, which would lead you to a fuel delivery issue.

Looking at the plugs is also a good idea. Are they black or tan? Are they wet after cranking?

i'll relay this to him, thank you