2008 Ninjette Will not run, I am clue less Please HELP!

[Klondike1020]

Hello

My 2008 ninja 250 had been sitting for a couple months and It was starting very hard. Once it would start it only would run on choke and would Immediately stall when the throttle is twisted even the smallest amount.

I pulled the Carbs and cleaned them out cleaning them very carefully and they had lots of varnish like yellow build up from the old fuel with a tiny bit of corrosion but the jets did not seem to be clogged in any way. I reassembled the carbs and then blew into the atmospheric side of the carb to cause the vacum slide to lift. Both slides operated freely. I drained the tank and tested the fuel pump which pumped a lot of fuel.

I put the carbs back on cleaned the air filter and gassed her up. She started hard and would only Idle on choke. After about 10 min of warm up I rev'ed the piss out of it and went to put it in first. It stalled out and now it will not even run on choke.

Does anyone have any IDEA what my next step should be in problem solving the bike.

side note.... My main jet needles do not have clips or notchs on them for adjustment .... Stock are not adjustable ?

[Motofool]

Have you verified that the carbs are being supplied with abundant fuel?

Any restriction in the supply system or lack of ventilation in the tank could cause that.

What fuel pump do you refer to?

[Klondike1020]

The diaphragm pump that is built into the petcock. If I remove the fuel line to the carb it pours out abundant fuel ! also I have a dripping fuel leak from one of the float bowls that I need to address.

So I do believe that plenty of fuel is going to the carbs.

Originally Posted by Motofool

Have you verified that the carbs are being supplied with abundant fuel?

Any restriction in the supply system or lack of ventilation in the tank could cause that.

What fuel pump do you refer to?

[DaBlue1]

Originally Posted by Klondike1020

..... My main jet needles do not have clips or notchs on them for adjustment .... Stock are not adjustable ?

Stock needles can be adjusted by adding washers (shimming).

Originally Posted by Klondike1020

......If I remove the fuel line to the carb it pours out abundant fuel ! also I have a dripping fuel leak from one of the float bowls that I need to address.

Fuel should only flow if the petcock is on PRI. If fuel flows with the bike not running, the fuel line disconnected from the carb and the petcock on the ON position, then you have a bad petcock. You need to re-do your carb work and check for vacuum leaks and loose carb boots.

[csmith12]

http://www.ninjette.org/wiki/My_Bike_Won%27t_Start

Good luck!

[Klondike1020]

I understand how the prime works and the on setting. When it is on and I turn the motor over it pumps fuel via the diaphragm pump that is built into the pet cock.

I may just leave it to the on position and try startign it and that could indicate an issue with the pump and vacuum . but it seems to work well when I un hook the fuel line and turn key(turn the motor over)

I cannot figure it out. if i spray fuel into it it will run a bit
If I run it on choke it will idle but not run.

Could it be the Mass air flow sensor or some kind of electronic issue?

[csmith12]

When was the last carb cleaning? Maybe it's time to clean em, especially those idle jets. Your op states it's been sitting for a time. When it does run, can you rev it without dying?

[cuong-nutz]

Vacuum lines hooked up properly? Carb diaphragms not ripped? Idle screws weren't messed with? Carb synched?

[Motofool]

Originally Posted by Klondike1020

The diaphragm pump that is built into the petcock. If I remove the fuel line to the carb it pours out abundant fuel ! also I have a dripping fuel leak from one of the float bowls that I need to address.

So I do believe that plenty of fuel is going to the carbs.

There is a little filter inside the hose, right at the entrance of the carb; did you check that the hose supplies freely into the carbs?

That diaphragm is not a pump, it is the actuator of a vacuum operated valve.
It is a safety device to avoid fuel flowing out of the tank while the engine is off (zero vacuum condition).

As one of the bowls is overflowing, you have a fuel level problem that needs to be addressed first.
Your jets can only control the mix if they work against an specific level of fuel in the bowls.
Either your valves or floats are bad or you inadvertently modified their adjustment during the cleaning process.

[Klondike1020]

@ csmith12 - I did not take our or adjust any idle screws. I did not even notice them.
I just sprayed carb cleaner through every little orfice I could see in the Carb with the little red straw until it blasted out at the other end of whichever hole it was. I did remove the Diaphram for the slides and the floats ect. but thats about it

I did not sperate the carbs so they should be perfectly Synced? !!!

It does not rev up at all. just idle w choke or not running at all.

Originally Posted by Motofool

There is a little filter inside the hose, right at the entrance of the carb/// inadvertently modified their adjustment during the cleaning process.

I did not check the little filters I just sprayed carb cleaner through them and it seemed to blast right through. I was very carful with the floats and valves I am certain I did not bend them or move anything. Also symptoms have not changed pre carb clean and post carb clean

@ cuong-nutz
None of the soft parts were ripped or dry rotted . they seem fine.


Thank you for all the help , I will be going through things all over again to see whats up

this is the old crashed ninja I putt around on for fun thats why its so neglected :/

[Klondike1020]

I think I may have an IDEA ,,, The slides have a hole in them that is to the front or back in line with the needle.... if I put the slides in back wards could it cause these problems?

[csmith12]

Originally Posted by Klondike1020

@ csmith12 - I did not take our or adjust any idle screws. I did not even notice them.
I just sprayed carb cleaner through every little orfice I could see in the Carb with the little red straw until it blasted out at the other end of whichever hole it was. I did remove the Diaphram for the slides and the floats ect. but thats about it

I did not sperate the carbs so they should be perfectly Synced? !!!

It does not rev up at all. just idle w choke or not running at all.
/

Cleaning the carbs is just a bit more than spaying and cleaning the surface areas. The main deal is to clean the jets. Specifically those little idle jets.

Check this to clean the jets

Link to original page on YouTube.

[dino74]

Originally Posted by csmith12

Cleaning the carbs is just a bit more than spaying and cleaning the surface areas. The main deal is to clean the jets. Specifically those little idle jets.

One of my 250s was sitting around for 6 months and it wouldn't start. First cleaned in the same manner you described, it barely ran. I then took the carb completely apart and soaked it in Berryman's Chem dip. It started right up with no problems

[r6boater]

There is no MAF on carbs.

Slides wont go in backwards.

We had a similar sounding problem with Draik's '08. We cleaned (fully, by taking our all the jets), shimmed the needles and have to keep in on PRI... seems to work fine for us now.

[Klondike1020]

Originally Posted by r6boater

There is no MAF on carbs.

Slides wont go in backwards.

We had a similar sounding problem with Draik's '08. We cleaned (fully, by taking our all the jets), shimmed the needles and have to keep in on PRI... seems to work fine for us now.

The slides cannot go in backwards? I thought they fit both ways. But either way I have the bike running and iddling in the back of the ware house right now. If I hold it wide open on choke it will sputter and run just above idle RPM and if I leave the throttle at idle it will idle. Everything else is stall.

I spray carb cleaner into the air box and rev it up and it will roar to life

Does that mean it must be a fuel delievery problem?

I sprayed Carb cleaner through each jet and it seemed to blast right through un obstructed....

I sprayed straight up through the main jet
Through the two little jets when you look through the venturi
I sprayed through the float valves

The carb did not look dirty it just had a yellowish film built up in it. Very little corrosion.

I guess I should just pull the carbs and try and try again ???

What other jets may I have missed?
Is it really necessary to remove the brass main jet to clean it?

[r6boater]

I've always figured it is. You can take them out, hold them up to the light to veify they are clean. blow air through the carb with out the jets in it. Since you are pulling the carbs off anyway, you might as well fully disassemble and clean them.

When you are trying to get it started/rev it, do you ahve the airbox back on? If not, you could be just simply be having a "too-lean" condition.

[DaBlue1]

Even though your carbs may be clean, there may be other reasons that may be your problem. It sounds like your engine may be lean with throttle openings.

Typical Lean Conditions:

- Poor acceleration; the engine feels flat.
- The engine won't respond when the throttle is snapped open, but it picks up speed as the throttle is closed. (A too-large main jet also mimics this symptom.)
- The engine runs hot, knocks, pings and overheats.
- The engine surges or hunts when cruising at part-throttle.
- Popping or spitting through the carb occurs when the throttle is opened. Or popping and spitting occurs through the pipe on deceleration with a closed throttle.
- The engine runs better in warm weather, worse in cool.
- Performance gets worse when the air filter is removed.

Here are some other things to look at from the TroubleShooting Guide

Poor Running at Low Speed:

Spark weak:
Battery voltage low
Spark plug dirty, broken, or maladjusted
Spark plug cap or high tension wiring trouble
Spark plug cap shorted or not in good contact
Spark plug incorrect
IC igniter trouble
Crankshaft sensor trouble
Ignition coil trouble


Fuel/air mixture incorrect:

Pilot screw maladjusted
Pilot jet, or air passage clogged
Air bleed pipe bleed holes clogged
Pilot passage clogged
Air cleaner clogged, poorly sealed, or element missing
Choke plunger stuck open
Fuel level in carburetor float bowl too high or too low
Fuel tank air vent obstructed
Carburetor holder loose
Air cleaner duct loose


Compression low:

Spark plug loose
Cylinder head not sufficiently tightened
No valve clearance
Cylinder, piston worn
Piston ring bad (worn, weak, broken, or sticking)
Piston ring/groove clearance excessive
Cylinder head warped
Cylinder head gasket damaged
Valve spring broken or weak
Valve not seating properly (valve bent, worn, or carbon accumulation on the seating surface)


Other:

IC igniter trouble (also see the NinjetteWiki; http://www.ninjette.org/wiki/Ignitor_problem)
Carburetor not synchronizing
Vacuum piston doesn’t slide smoothly
Engine oil viscosity too high

[Motofool]

Your mix is too lean to sustain internal combustion for anything other than minimum airflow.

You have a fuel delivery problem, but only you can find where it is.

When you twist the throttle, you are opening the butterfly valve that only allows more air to come into the engine.

The Bernoulli effect of that airstream sucks fuel from all the jets.
When that doesn't happen, that cold air cools the internal flame and subsequent combustion stops happening.

Why only so much fuel is being delivered by your jets?
The answer to that question will solve this mystery.

[rojoracing53]

Originally Posted by Klondike1020

The slides cannot go in backwards? I thought they fit both ways. But either way I have the bike running and iddling in the back of the ware house right now. If I hold it wide open on choke it will sputter and run just above idle RPM and if I leave the throttle at idle it will idle. Everything else is stall.

I spray carb cleaner into the air box and rev it up and it will roar to life

Does that mean it must be a fuel delievery problem?

I sprayed Carb cleaner through each jet and it seemed to blast right through un obstructed....

I sprayed straight up through the main jet
Through the two little jets when you look through the venturi
I sprayed through the float valves

The carb did not look dirty it just had a yellowish film built up in it. Very little corrosion.

I guess I should just pull the carbs and try and try again ???

What other jets may I have missed?
Is it really necessary to remove the brass main jet to clean it?

Correct the black plastic slides only go in one way.

[CZroe]

Missing needle seats.