06 ninja 250 starting problems

[DRchipper]

Hey guys, I need a little help here. I have an 2006 250 with about 6000 miles. For the past year or so it's been hard to start and because of this it hasn't been ridden much.
First off it has fresh gas with sea foam in it and new spark plugs as of this week. I've also cleaned the carb twice since the problem began. The first time I cleaned it one of the pilot jets was clogged so I thought I solved the problem but it wasn't any better.
Now the problem... when I start it I have to have the choke on naturally, but it takes longer to start than it should and when it does start it runs right around 1500 rpms and will slowly go up to 2000..normally it would go up to 6000 or so with the choke. I let run a couple minutes but when I try to take the choke off it starts to die... if I give it throttle it starts to die. It takes 5 or 10 minutes but it will eventually warm up to where I can take the choke off and use the throttle. After it's warmed up it runs perfect and idles perfect. I've put couple hundred miles on it since changing gas and adding sea foam so the sea foam should've done its thing by now. What am I missing?

Thanks in advance!

[csmith12]

Welcome Dustin!

Bummer about your bike running issues but... let's start with the basics.

There are 2 jets per carb, one main and one pilot/idle. Did you clean both? Your symptoms would indicate a clogged pilot. There is a thread here somewhere titled "Hidden Passages." Find that thread to "REALLY" get into cleaning all the areas of the carb that need to be looked at.

[ducatiman]

OP your description indicates the enrichener circuits (choke or starter circuits, whatever you choose to call them) are compromised as well.

Next to the main and pilot openings, there lives a fixed "jet" (actually a pickup tube) its circuit continues through the choke plungers and apparently needs to be addressed ....along with all the usual suspects.

This starter circuit is activated when the plungers are "open"...otherwise the circuit is closed shut.

[Triple Jim]

The fact that it runs OK when fully warm makes me think it's not going to be a waste of time to check the valves.

[Ghostt]

Always make sure the valves are adjusted properly, otherwise you might be chasing your tail, so to speak.

[ducatiman]

an '06 with 6000 miles has done a lot of sitting

valid point in checking valves, though I'd not disregard carbs afterwards

[Ghostt]

Definitely could be the carbs, the valves are one of those overlooked things, and should be done regardless to have a solid baseline for diagnostics, and performance. It's also one of the most things people don't do per maintenance, like servicing the calipers, unitrack, etc.....

Is there an inline fuel filter installed? If not might have sucked something into the carbs?

[Triple Jim]

Other than possibly having the enrichers not working (cable broken?) I don't see how the carbs could be the problem. I say this because Dustin said:

"After it's warmed up it runs perfect and idles perfect."

[DRchipper]

Thank you both much! I know the mains and pilots are clear... i had no clue those others were for the choke! Next time I get a chance to work on it I will look into those.

[DRchipper]

Sorry didn't see other replies at first. If the enriches are ok I'll look into the valves. Maybe even if they aren't ok. Thanks again

[DRchipper]

Ok so i cleaned the enrichment jets good and it definitely was a problem. Now it starts on choke and goes to about 6k.. I let it run there a little while and try to back off the choke and it starts to die. If I turn up the idle (further than where it should be) i can get it to run without choke but as soon as I try to give it throttle it wants to die out. The pilot circuit seemed to be clear and The idle mixture screws are turned out 2 1/2 turns. I noticed there are 2 shims on the needle and I'm 85% sure they were above the clip when I took it apart so that's where they are now. I do know it had bigger jets put in at some point. Could it still be a valve issue? Any addition help is much appreciated.. thanks

[DRchipper]

Also I should add that when it is warmed up to where I can use the throttle, if I rev to 6 or 7k or whatever rpm it's slow to come back down to idle.

[Triple Jim]

You pilot circuits are almost certainly not completely clean. The needles/needle jets aren't active when trying to get the engine to idle.

Shims on the needle don't do anything unless they're under the clip where they can raise the needles a little. That's sometimes done on these to prevent lean midrange surging.

[jkv45]

Carbs are not right.

Might also be a vacuum leak.

Valves may need adjustment.