2006 ninja 250 wont rev!?

[Sig99]

hey guys. so i recently picked up a 2006 ninja 250r. i just cleaned the carbs, and threw new plugs in it and it wont rev. when i spray start fluid into the air box, it will rev as i spray, but with out starter fluid it will only idle. if i try to rev without starter fluid it just bogs out. i blew compressed air through the jets, and through where the jets screw in. also blew it through every hole i could see. ( i only pulled the float bowls off ) what part of the carbs would be causing this thing to completely die when i give it any throttle? i didnt pull the diaphragm covers off, could there be a ripped diaphragm? dont want to pull the carbs back off until someone can give me a ballpark as to whats not letting it rev without starter fluid. thanks for the help in advance guys.

[ducatiman]

First thing...verify the petcock is actually delivering adequate fuel to the float bowls

[Sig99]

Originally Posted by ducatiman

First thing...verify the petcock is actually delivering adequate fuel to the float bowls

I replaced the fuel filter, and fuel line today as well. I should’ve mentioned that beforehand. Gas flows heavily out of petcock, there’s no link in the line, and it’s a good size fuel filter. Not oem, but it’s a mesh screen filter that can flow plenty.

While writing the above, I ran downstairs, loosed the drain screw on the bottom of the carbs, and I have little to no gas in the right side carb bike is on the center stand so its level at all times. Didn’t check the left, as I left my extensions at work and don’t want to pull the carbs. back off tonight. I then used fresh fuel line to go straight from good flowing petcock, right into carbs. Still no fuel in right side carb. I assume very little or none as well in the left side carb. Just didn’t check due to not being able to acess it tonight. Although it ran and spiked to 4k fully choked and then quickly died. Got it to do that twice. What do you think? Is the pet cock not flowing fuel once the bike starts cranking? It doesn’t flow in the on position when bike is off and I believe that’s how it’s supposed to be. But I set it to the prime setting on the petcock (don’t worry I was catching the gas from the little vacuum hole on the bottom with a container) but still had the same result of no gas in the carb

Edit: id like to add that i did blow compressed air through the fuel lines that go into the carb while connected to the carb, and air did come from around the float valves.

[Cafe Racer]

You probably have a float issue.

When I buy a new to me bike that has been sitting I only check for spark.
I never try to get it running. The first thing that needs to be done is to order a carb rebuild kit from ducatiman. Then proceed to dissemble the entire carb, soak in an ultrasonic bath with 25% simple green, then wire floss every jet, passage way and hole. Followed by spray carb cleaner and compressed air.
Adjust the float level to spec and reassemble. The nice thing about the 250 ninja is you do not have to dissemble the carbs from each other most of the time.

You still have dirty carbs and unverified float levels.

[ducatiman]

Originally Posted by Sig99

I replaced the fuel filter, and fuel line today as well. I should’ve mentioned that beforehand. Gas flows heavily out of petcock, there’s no link in the line, and it’s a good size fuel filter. Not oem, but it’s a mesh screen filter that can flow plenty.

While writing the above, I ran downstairs, loosed the drain screw on the bottom of the carbs, and I have little to no gas in the right side carb bike is on the center stand so its level at all times. Didn’t check the left, as I left my extensions at work and don’t want to pull the carbs. back off tonight. I then used fresh fuel line to go straight from good flowing petcock, right into carbs. Still no fuel in right side carb. I assume very little or none as well in the left side carb. Just didn’t check due to not being able to acess it tonight. Although it ran and spiked to 4k fully choked and then quickly died. Got it to do that twice. What do you think? Is the pet cock not flowing fuel once the bike starts cranking? It doesn’t flow in the on position when bike is off and I believe that’s how it’s supposed to be. But I set it to the prime setting on the petcock (don’t worry I was catching the gas from the little vacuum hole on the bottom with a container) but still had the same result of no gas in the carb

Edit: id like to add that i did blow compressed air through the fuel lines that go into the carb while connected to the carb, and air did come from around the float valves.

if that is the case, then exactly where would a fuel restriction occur? Something not adding up here...bowls should be getting fuel at least.

How long was this 13 year old bike sitting dormant?

[Sig99]

Originally Posted by ducatiman

if that is the case, then exactly where would a fuel restriction occur? Something not adding up here...bowls should be getting fuel at least.

How long was this 13 year old bike sitting dormant?

It sat for 2 years outside. Okay so here’s the update. When I try to blow through the fuel line going into the carb, I can’t blow through it. But when I force 120 psi of air in it it’ll have some come out, but when trying by mouth, it will not let me blow any air into the carbs. The petcock pisses gas from the vacuum hole in the on and reserve/prime position. I ordered a petcock that supposedly works with the bike just for the he’ll of it due to it being 7$. But that wouldn’t cause my issue here would it? Because I literally can’t even blow through the brand new fuel line while it’s attached to the carbs. So there’s no way fuel can get in them either since my breath can’t. I also tried blowing while cranking bike, same result.

[DannoXYZ]

Originally Posted by Sig99

It sat for 2 years outside. Okay so here’s the update. When I try to blow through the fuel line going into the carb, I can’t blow through it. But when I force 120 psi of air in it it’ll have some come out, but when trying by mouth, it will not let me blow any air into the carbs. The petcock pisses gas from the vacuum hole in the on and reserve/prime position. I ordered a petcock that supposedly works with the bike just for the he’ll of it due to it being 7$. But that wouldn’t cause my issue here would it? Because I literally can’t even blow through the brand new fuel line while it’s attached to the carbs. So there’s no way fuel can get in them either since my breath can’t. I also tried blowing while cranking bike, same result.

No, you've got several independent issues:

1. Inline filter inside fuel-line has been reversed and crushed-in on itself, or it's completely filled up with crud and not passing fuel.

2. and/or .... fuel-distribution line between carbs clogged and not delivering petrol to float-bowls.

3. and/or float-valves stuck due to dried petrol varnish acting as glue.

4. petcock's diaphragm ripped and not opening petcock's fuel-line.

5. new petcock (when it arrives) will not fit because it's too short, selection-handle will hit bottom of tank, and tilt petcock to prevent seal with tank.


I suggest removing carbs and sending them to ducatiman for full-refurb job. This way, you only have to remove carbs once. Rather than doing one trick once. Then having carbs still be problematic and having to yank them yet again, and trying slightly deeper clean. Only to find it didn't work and yanking them yet again for more desperate attempt at "cleaning" to have it not work... etc.

[Sig99]

Originally Posted by DannoXYZ

No, you've got several independent issues:

1. Inline filter inside fuel-line has been reversed and crushed-in on itself, or it's completely filled up with crud and not passing fuel.

2. and/or .... fuel-distribution line between carbs clogged and not delivering petrol to float-bowls.

3. and/or float-valves stuck due to dried petrol varnish acting as glue.

4. petcock's diaphragm ripped and not opening petcock's fuel-line.

5. new petcock (when it arrives) will not fit because it's too short, selection-handle will hit bottom of tank, and tilt petcock to prevent seal with tank.


I suggest removing carbs and sending them to ducatiman for full-refurb job. This way, you only have to remove carbs once. Rather than doing one trick once. Then having carbs still be problematic and having to yank them yet again, and trying slightly deeper clean. Only to find it didn't work and yanking them yet again for more desperate attempt at "cleaning" to have it not work... etc.

Floats were stuck. Ordered a kit from ducatiman and rebuilt them. Bike runs now, rides, and revs. But I have like surges of power. So from idle to 10 grand, it accelerates decently hard but not as much as it’s supposed to. Once I hit 10k, it explodes with power and actually lifted the front wheel on the first - second shift. Why am I not getting full power until after 10k?

[jkv45]

Originally Posted by Sig99

Floats were stuck. Ordered a kit from ducatiman and rebuilt them. Bike runs now, rides, and revs. But I have like surges of power. So from idle to 10 grand, it accelerates decently hard but not as much as it’s supposed to. Once I hit 10k, it explodes with power and actually lifted the front wheel on the first - second shift. Why am I not getting full power until after 10k?

My guess is the slides are not lifting properly (too slowly) for one reason or another.

[Sig99]

Originally Posted by jkv45

My guess is the slides are not lifting properly (too slowly) for one reason or another.

Well I discovered I forgot to put the air filter in. So I put it in, and went for a ride, bike ran much better.. I figured I’d go down to pepboys and spend 10$ on a vin check so I can go register this thing. About 25 minutes down the highway, I lost power. All power, and then the bike died. I’m currently waiting for my progressive road side assistance, (thank god I got insurance literally yesterday) and so far I’ve tested for spark, I do have strong spark, and my 7$ fuel petcock off eBay has failed. Gas flows out in the on position with the bike not running. I suspect this to be my issue, but will investigate further once I’m home. Any ideas? Bike just started to lose power little by little and then died (acting as if it’s running out of gas) I was cruising around 80mph. Also, What’s a cheap strong petcock I can buy that won’t fail in 17 miles? New one from Kawasaki is like 100$. Not interested in paying that at all. Lol

[jkv45]

Bummer.

There isn't a good aftermarket replacement petcock out there that I've seen. Most are manual (not vacuum) and not long enough to be able to turn them on and off.

There are rebuild kits, but some are as pricey as a complete new petcock.

[DannoXYZ]

So BOTH your original and new petcock flow fuel in ON position? Should only flow when there's vacuum in vacuum line. Something's wrong with both of them.

I believe this is rebuild-kit for pre-gens:https://www.ebay.com/itm/323531028088

[MikeCL]

Originally Posted by jkv45

Bummer.

There isn't a good aftermarket replacement petcock out there that I've seen. Most are manual (not vacuum) and not long enough to be able to turn them on and off.

There are rebuild kits, but some are as pricey as a complete new petcock.

I didn't know that about the aftermarket petcocks.