Need Help Diagnosing Bike That Wont Run

[Yondaime]

Hello! I have a 2010 Ninja 250 that I haven't driven in a few years. The only mods I have done to the bike is a K&N filter pod and I removed the Airbox. I did some reasearch and everything that I read pointed me towards removing and cleaning the carbs.

I went ahead and removed the carbs and cleaned them thoroughly but I still can't get the bike to run!


If I spray starter fluid into the air intake it will run for a few seconds.

If I blow into the "fuel overflow" line at the top of the carburetors the engine will stay running indefinitely as long as I keep blowing a small amount of air into the hose.

I opened the bleeder valve at the bottom of the carburators and it does appear to be getting fuel.

I have already tried changing the spark plugs!

Any tips or help would be appreciated! Thank You!

[cuong-nutz]

Does it need choke to run? My guess is your carbs are still dirty and that your pilot jets are dirty.

[Yondaime]

Originally Posted by cuong-nutz

Does it need choke to run? My guess is your carbs are still dirty and that your pilot jets are dirty.

The motorcycle will not run with the choke in either position! Which brings up a good point.

When I opened up the Carbs to clean them I noticed the "Enricher Choke Pickup" was clogged. Is there anyway to clean this orifice?

[cadd]

This might be an obvious question....but did you replace the fuel that was a few years old that's in the tank before trying to start it?

[Yondaime]

The old fuel was drained/replaced and all the jets including the pilots (the two small ones) were cleaned. I'm going to remove the carbs again tomorrow and see if I can clean the enricher choke pickup.

I have also tried placing the petcock valve on prime and still no dice in case somebody was wondering.

Any help or suggestions are appreciated!

[JohnnyBravo]

Soak them a while in a lil bucket with cleaner of your choice... Blow compressed air through orifices (wear goggles/safety glasses)

[jkv45]

A good soak in carb cleaner and cleaning in an ultrasonic cleaner would be the best.

Did you run a small soft wire through the Pilot jets and the Main jets, and clean out the small holes in the jet holder? Did you remove the caps over the idle mixture screws and remove the screws? That's the only way you can clean the idle mixture circuit.

There's more to cleaning the carb than making it look clean.

[Yondaime]

Originally Posted by jkv45

A good soak in carb cleaner and cleaning in an ultrasonic cleaner would be the best.

Did you run a small soft wire through the Pilot jets and the Main jets, and clean out the small holes in the jet holder? Yes Did you remove the caps over the idle mixture screws and remove the screws? Not yetThat's the only way you can clean the idle mixture circuit.

There's more to cleaning the carb than making it look clean.

Even if the idle mixture was off... Wouldn't the bike run fine at higher rpms?


The only two things I can think of are the idle mixture and choke enricher pickup...

I'll try cleaning both and will post results.



I may have to do a soak... I didn't want to spend the 25$ for the can but I might not have an option at this point!

[jkv45]

Originally Posted by Yondaime

Even if the idle mixture was off... Wouldn't the bike run fine at higher rpms?
(SNIP)

From the sound of it the idle and enrichener circuits are blocked, so chances are it wouldn't start or stay running.

A very thorough cleaning is needed.

[cuong-nutz]

You need some thin strands of copper wire and poke up through the tiny orifices.

[Yondaime]

I removed the carbs and rechecked everything again.

Every jet and orifice was/is clean.

I removed the idle mixture screws and cleaned them out even though they looked clean as well.

I noticed that if I plug the carburetor intake with my hands that the engine will turn on but it will not run if I remove my hand. The bike appears to need some sort of constant vacuum in front of the butterfly valves.

Whenever I first removed the carbs to clean them, I went ahead and removed the air box, replacing it with a K&N Filter and I didn't rejet. I figured the bike would at least run even though the a/f ratio would be a little off without having to rejet



Can somebody verify that these hoses are correct?

[cuong-nutz]

Did you pop the idlle mixture screw covers, remove the screws/needles and flush it out?

Did you mess with the idle adjust screw knob? clockwise increases idle speed.

[Yondaime]

Originally Posted by cuong-nutz

Did you pop the idlle mixture screw covers, remove the screws/needles and flush it out?

Yes

Did you mess with the idle adjust screw knob? clockwise increases idle speed.
I turned the screw all the way in and then went out 2.5 turns

It's wierd that the bike will turn on and idle as long as I place some sort of restriction in front of the carburetor intake.

I'm going to try increasing the idle speed next.

Thanks for the help trying to diagnose the issue. I found a guy with a similar problem on another forum but he never posted if he did or didn't fix it!

[cuong-nutz]

What do you you have the idle mixture screws set at? You'll want to richen it up. You could shim your jets as well. cheap temp fix.

[Yondaime]

Originally Posted by cuong-nutz

What do you you have the idle mixture screws set at? You'll want to richen it up. You could shim your jets as well. cheap temp fix.

I finally got it to run today after tasking out the floats entirely. I WRONGLY assumed that since they moved up and down that they were fine.

The bike is finally running but it is still not wanting to run "right" i.e. finicky throttle and it dies if I give it gas too fast! Thankfully there are TONS of post about people having this problem at this stage in the game now.

I had the idle mixtures screws at 2.5 turns out from completely being all the way in. I'm going to run by the store to pick up some shims, thanks for reminding me!

[cuong-nutz]

So what exactly was the issue?

[Yondaime]

Originally Posted by cuong-nutz

So what exactly was the issue?

I cleaned everything out except for the actual "float valves". I wiggled the floats up and down and falsely assumed that they weren't gummed up. I also figured that since there was fuel in the bowls, when I checked them by opening the drain valve, that the floats were fine and working!

I ended up removing/cleaning those two float valves and it finally started up.

Now It will idle perfect but it doesn't run very well if I jab the trottle (dies) and it wont' go above 7k rpm. I'm going to try installing those shims and setting the fuel mixture screw to 3 turns out!

Would 3 turns out make it richer than the 2.5 people recommend?

Thanks!

[cuong-nutz]

Turning it out gives it more gas/makes it richer.

http://www.ninjette.org/forums/showt...4&postcount=34
http://faq.ninja250.org/wiki/How_to_...e_your_jetting
http://www.250ninja.net/articles/ninja_250_jetting.html

[Yondaime]

I also forgot to mention that the choke doesn't seem to do anything for the bike. I tried jamming some copper wire into the "enricher (choke) pickup" but it didn't appear to go anywhere I'm going to try and clean out the choke mechanism as much as possible tomorrow again.

Will post results:

[cuong-nutz]

From what I remember is that the passage necks down and I think there's a bleed hole on the side of the body.

[Yondaime]

Originally Posted by cuong-nutz

From what I remember is that the passage necks down and I think there's a bleed hole on the side of the body.

It's the bullet looking thing with the rubber tip!






It goes at the top of this picture connected to the plastic floats!



I just assumed it was working properly because the bowls had fuel in them. I figured that if the bowls didn't have any gasoline in them, the needle valve wasn't working. It turns out that even though you have fuel in the bowls, the bike might no run correctly unless they are VERY VERY clean!

[jkv45]

Read this section - http://faq.ninja250.org/wiki/How_do_...n_the_carbs%3F

[cuong-nutz]

I was referring to the choke puckup passageway

[Yondaime]

Originally Posted by cuong-nutz

I was referring to the choke puckup passageway

Oh Ok! I'll check that I tommorow as well! I'll check out those links posted as well!

Thank You!

[Klondike1020]

Yeah I had to clean mine twice and three times before I got it running good ...

used guitar string scraps to clean those darned orifices.

Good luck, easy on the soft parts

[Yondaime]

I got the bike running at higher RPMS now!

I followed the tube for the "enricher (choke) pickup" and it was completely clogged. I finally was able to get a hold of some compressed air and it opened right up!

Is there any reason why I have to really open up the idle mixtures for the bike to run? They are almost all of the way out!


Thanks!