Cleaned Carbs, Replaced Gas, Still having engine problems.

[azwillnj]

WARNING: long post, skip to the end for the cliff notes.....

I just bought a 2007 ninja 250 with about 14k miles on it... for $250!!. The previous owner was going around a turn at about 20mph and halfway through the turn the road surface went from asphalt to gravel and he slid it out destroying the fairings on the front. While the fairings are destroyed, the frame and mechanical components are in perfect shape. I am going to make it into a streetfigher, I bought a round headlight and some handlebar mirrors.. I'll post pictures when I'm done..

On to the engine problems...

The previous owner said he had cleaned the carbs and adjusted the valves just prior to selling the bike but for some reason it still wouldn't run. When I first got the bike back I drained the tank, put some new premium fuel in it and installed the tank, plugged everything in and actually got it to start and idle. As soon as I TOUCHED the throttle the engine would die, and choke seemed to so nothing and even after letting it rough idle for about 10 mins I still couldn't get it to go over idle. Exact same symptoms at this thread (see video): http://www.ninjette.org/forums/showthread.php?t=21775

I did some looking on this forum and ninja250 and decided to do a very through cleaning of the carb. I took it off, cleaned the jets, drilled out the mixing screw plugs, cleaned them, backed them 2.5 turns off the seat. Flipped it over, checked the diaphragms, made sure there were no rips or damage, re-seated the seals carefully and closed them, installed it back in the bike and attached everything back up.

The bike started and ran like a champ, throttle was responsive it idled fine. I revved it up to about 10k a few times, dropped it back to idle and let it sit there for a little.. about 90 seconds later it just died. Thought it might have been something with the choke, dropped the choke completely off and started it back up, it idled fine but as soon as I TOUCHED the throttle it would die no matter where the choke was set. I tried starting it a few times after that and it's doing the exact same thing as before I cleaned out the carbs.

I looked inside the gas tank and it is perfect, looks like nothing has ever been in there. The only thing I can think of at this point is that the petcock on the tank is dirty or not working properly, maybe there's some debris in it that is coming back into the carbs? Thus, my next attempt at fixing this thing is going to be removing and cleaning the petcock, I will also be replacing the spark plugs (they are on order from AutoZone and should be here tomorrow). Additionally, I'm also going to install an inline fuel filter to make sure that there is nothing getting in the carbs and re-clean the carbs (again!). In the mean time, is there anything else I can try or any suggestions anyone has?


------------
TLDR:

Things I have done:
-Drained the tank
-Inspected the tank (no rust or wear of any kind)
-Cleaned the Carbs (mixing screw set, float height checked, pilot and main jet cleaned)
-Checked the coils to make sure they were plugged in
-Charged the battery

Result:
-Bike ran for about 5 mins, throttle was responsive, idle was fine, then it just died.
-Currently bike will idle, but that's it, as soon as you touch the throttle it dies.

Next Steps:
-Inspect petcock on fuel tank
-Install inline fuel filter
-Re-clean carbs
-New spark plugs
-Sync carbs


Thanks for the help,
Alex.

[JLinde1339]

Good find for $250.

Is everything else stock on it? Airbox, needles, jets, exhaust?

[azwillnj]

Originally Posted by JLinde1339

Good find for $250.

Is everything else stock on it? Airbox, needles, jets?

Yes, the only thing different is the exhaust, it has a single muffler on the right side. Not sure of the brand, sorry.

I don't think it needs re-jetting if it has an exhaust.. right?

[CZroe]

Sounds like a crazy good deal. My friend had problems until he replaced the battery even when it tested good. Try connecting a mobile jumpstart battery while it's running to see if that makes a difference.

[gilmorec61]

Re clean the carbs and tell us what happens. Ive cleaned a plenty carbs in my life, and ive seen that even if you clean it nice and good the first time, and it starts up then dies like you explained. What normally happens is that there is still crap in the fuel line or gas tank and it gets back in there and clogs those jets. So as i said, clean them out again and clean out the fuel line and even maybe pour some fresh gas in the tank and shake it up then drain it. The start it and tell us what happens

[JLinde1339]

Originally Posted by azwillnj

Yes, the only thing different is the exhaust, it has a single muffler on the right side. Not sure of the brand, sorry.

I don't think it needs re-jetting if it has an exhaust.. right?

Depends on how the exhaust flow may have been changed. Even going from stock dual exhaust to aftermarket duals will require some adjustment. Changing the duals to a single exhaust setup would require a rejet, almost guaranteed. If Skippii sees this, he might be able to order some input on going to a single, as he has done that. If not done right, the engine may have trouble expelling all the exhaust that it needs to.

[Zaydoc]

Turn the mixture screws out to 3 and you might need to raise the needles to 2-3 washers.

[azwillnj]

Originally Posted by Zaydoc

Turn the mixture screws out to 3 and you might need to raise the needles to 2-3 washers.

Why? What does that do? (not doubting you, just want to learn more about how these things work)..

Also, what do you mean by 2-3 washers, I assume i shim the needles in the diaphragm? Is there a page on this at ninja250?

[g21-30]

You should consider really cleaning the carburetors! Get some Gunk Carb Cleaner (with the drip tray) and do each carb one at a time. Then blow them out with compressed air and reassemble. A gasket kit with small parts would be a wise investment, also.

[azwillnj]

Originally Posted by g21-30

You should consider really cleaning the carburetors! Get some Gunk Carb Cleaner (with the drip tray) and do each carb one at a time. Then blow them out with compressed air and reassemble. A gasket kit with small parts would be a wise investment, also.

I don't think I need to go that crazy, the carbs are completely spotless, they look like they're new.. I'll take some pictures when I take them apart again.

[JLinde1339]

An inline fuel filter is a good cheap way to start the trouble shooting on this. That way you can see if the carbs are getting fuel or not. I found one at an auto parts store that came with hosing, so you don't have to worry about chopping up your stock fuel line.

[Zaydoc]

The mixture screws control the fuel for idle through the pilot jet. I know on my bike I've had to open my screws up to 4 turns now waiting on new pilot jets that are a size larger. I had somewhat of the same problem when I was tuning my carbs for my mods. As for the shims on the needles that is the next stage on the carbs for fuel. I had to move mine up alot just to get it over 3k rpms. That is a good start if your carbs are in fact clean and do not have any trash stuck in a jet or orifice hole.

[g21-30]

Originally Posted by JLinde1339

An inline fuel filter is a good cheap way to start the trouble shooting on this. That way you can see if the carbs are getting fuel or not. I found one at an auto parts store that came with hosing, so you don't have to worry about chopping up your stock fuel line.

The problem with the inline filters is that you need to get one that doesn't require fuel pressure, i.e. our bikes gas is gravity fed. If the filter is rated too high, it will restrict the flow of gas.

See the other posts related to inline filters.

[g21-30]

Originally Posted by azwillnj

I don't think I need to go that crazy, the carbs are completely spotless, they look like they're new.. I'll take some pictures when I take them apart again.

Spotless to one's eyes doesn't necessarily mean the carbs are clean. There are many orifices that need to be cleaned of varnish after sitting for extended times. Stumbling when applying gas, usually means the carb(s) is restricted in some way.

[azwillnj]

Originally Posted by g21-30

Spotless to one's eyes doesn't necessarily mean the carbs are clean. There are many orifices that need to be cleaned of varnish after sitting for extended times. Stumbling when applying gas, usually means the carb(s) is restricted in some way.

I followed the directions at ninja250 for cleaning out the carbs, I was thinking about taking the diaphragms (so I don't burst them) out and using compressed air to really blow the passages out.. thoughts?

[g21-30]

Originally Posted by azwillnj

I followed the directions at ninja250 for cleaning out the carbs, I was thinking about taking the diaphragms (so I don't burst them) out and using compressed air to really blow the passages out.. thoughts?

Definitely take the diaphragms out!! The compressed air will probably NOT remove all varnish from the passages. It's kind of like baked on grease on cookware. Takes a lot of elbow grease.

Check out this video:

Link to original page on YouTube.

[azwillnj]

Last night I did the following on the bike:

• Removed the petcock valve on the tank and checked it, opened it up and made sure the seal on the valve was fine and there were no debris inside... there was nothing wrong.
• Replaced the spark plugs, NGK stock plugs. (the old ones were very burnt and black but the electrodes looked fine)
• Changed the Oil and Oil Filter, Mobile1 10w-40 with a Fram filter.
• Removed the carbs again and cleaned the hell out of them.. I took out the floats, diaphrams, mixing screws, pilot jets, and the main jets. I soaked the jets and the mixing screws in carb cleaner for 45 mins, blew the passageways out with compressed air, then carb cleaner, then compressed air again.. finally, carefully putting everything back together and cramming it back on the bike.
• Last but not least, I filled a brand new 12A-A battery with acid and placed it on a trickle charger overnight.

I took pictures of the carbs and posted them online for your approval... http://imgur.com/a/PgTDC

I did not get a chance to test anything because the battery needed to charge overnight, I'll come back and post later with the results.

Alex.

[CZroe]

Let us know how it goes!

[g21-30]

Originally Posted by azwillnj

Last night I did the following on the bike:
I took pictures of the carbs and posted them online for your approval... http://imgur.com/a/PgTDC
Alex.

They look GREAT! Did you per chance already remove the inline filters for each carb and check them? I didn't look back in the comments to see if you already did that.

[azwillnj]

Originally Posted by g21-30

They look GREAT! Did you per chance already remove the inline filters for each carb and check them? I didn't look back in the comments to see if you already did that.

I don't think it has inline filters, unless I'm missing something the only fuel "filter" it has is on the pickups of the petcock valve in the fuel tank..and those were clear... What are you referring to?
Posted via Mobile Device

[azwillnj]

Just fought with the bike for about an hour. It's doing exactly the same thing as before, I'm pretty close to out of ideas. The only things left are syncing the carbs and adjusting the valves. I wont have time to do either until Sunday, but in the mean time, does anyone have any more suggestions?

Thoroughly Frustrated,
Alex.

[g21-30]

If the engine won't idle, the only syncing you can do is mechanical. You eyeball the carb plates and adjust them to what appears to be the same angle.

[azwillnj]

Originally Posted by g21-30

If the engine won't idle, the only syncing you can do is mechanical. You eyeball the carb plates and adjust them to what appears to be the same angle.

It will idle, roughly.. I am going to try and sync them tonight.. I'm not really sure how to deliver fuel while the tank is off. I'm sure I'll figure something out.

[azwillnj]

I adjusted the valves last night, turns out the previous owner mixed up his units and had the valves adjusted way off. I adjusted them perfectly and put everything back together... I was so happy because I thought I fixed the issue.. Bike started right up, ran great, responded to throttle, everything..

I let it idle and warm up so I could sync the carbs with my homemade yardstick/clear tubing/ATF manometer, as it warmed up the same **** started happening no response to the choke, throttle made it die. I thought it was just the carbs being really out of sync so I proceeded to sync them, they were off, but not by much... finished up and put the tank back on and it was still doing the same thing.

I even brought it out to see if I could ride it and it would engage 1st and idle, but that's it it would stall out and lurch to a halt when you touched the throttle.

I got discouraged and put it back in the garage, after about 20 mins I tried to start it back up again when it was a little cooler and it responded to the throttle just fine... What would cause it to run when cold but not when warmed up?!

My dad suggested replacing the coils as we had a similar problem with a lawn mower we had in the past.. Does anyone have any input? I'm out of ideas.


TLDR:--------------------
Adjusted the valves, synced the carbs, It's responsive when it's cold, but dies when warm. Thinking about replacing the coils, anyone have any suggestions?

Alex.

[zzrguy]

yes probably your coils. I heard of a guy having a similar problem his bike would run fine when cold but when it warmed up it stalled out and died. One of his coils was dead and the other was on the way out.

[Benjava]

It could be the coils but it really sounds like fuel starvation,
put a vaccum on the pet cock, route the fuel line into a gas can and watch the flow for a while to see how it goes and if it slows down open the gas cap. If it speeds back up again your tank venting is plugged up.

[KELPHYN]

Use an old spritz bottle with raw gas in it and spray down the carb carbs while the bike is running. If you can rev it up that way then it is still a fuel problem. For the coils...while it is run rough disconnect one coil and see if it changes. If it dies reconnect that one and try again disconnecting the other. If it dies again..I don't know..could be both coils are bad, but not likely. Have you checked your airbox and snorkel for debris? Read a artical one time a guy was having problems finally found a mouse nest in the snorkel. Also try just opening the gas cap if it is a venting problem. Good luck.

[wardie]

If you're certain the petcock and air filter are good and valves are set then I think you should open the gas cap and start the engine and let it run with the cap open , nothing ontop of it and see if this doesn't solve your problems.

You can check your coils for continuity when the bike gets them hot. I'd be surprised if it was the coils and not fuel starvation.

Best of luck these situations can try a mans patience. Wardie

[azwillnj]

I've tried running it with the fuel cap open and there was no change. I have also taken the 2 halves of the airbox apart and there was no debris..

I got good news about an hour ago though.. the slice app on my phone (awesome app) just told me my coils are out for delivery today, so we will know today if that's what it was. I'll come back and post with results tonight.

Thanks for all the help everyone.
Alex.

[choneofakind]

cut the battery box off your airbox while you have them seperated. Makes doing carb work easier in the future.

[azwillnj]

Coils didn't work, I want to set this damn thing on fire. Anyone want to buy a 2007 ninja haha.

Please help, what else is there?

[CZroe]

Get a carb dip?

[azwillnj]

Originally Posted by CZroe

Get a carb dip?

How far do I have to strip them down to dip them? I know I have to take the diaphragms out but do I need to separate them and take the choke needles off and everything too?

[TnNinjaGirl]

Is there anyone around that has a couple of known working carbs you could test out? Just to rule that option out.

Vacuum leak?

Maybe step back and have a friend look at it to see if there is anything obvious that has been overlooked. Or wait a couple of days with a fresh perspective.

Good luck!

[CZroe]

Originally Posted by azwillnj

How far do I have to strip them down to dip them? I know I have to take the diaphragms out but do I need to separate them and take the choke needles off and everything too?

I've never done it but I imagine that the bucket/basket combo has instructions. Even if you live outside of CA, you may find ones that meet CA regs. I've heard nothing but bad news about the CA formulations and even talked to one car guy who risked his business by smuggling the good kind in and hiding it from inspectors.

[azwillnj]

Latest Update:
I took the valve covers off and checked the timing, it was perfect.

I removed removed the airbox to see if the slides were moving normally and wasn't able to get it started. My roommate was playing with the mixing screws trying to get it to run better and i think they were way out of adjustment. I am going to re-adjust tonight and try to get it to idle again.

Cut the battery box off the airbox.

Made sure the stock jets were in the carbs and there was no tampering with them (no signs of someone trying to drill the jets out)

Sprayed some ether in the carbs while trying to start it and still nothing.

Ordered a CDI off eBay for $25 shipped!! Shipped from MA so I hope it will be here soon.

I took the spark plugs out and looked at them and the new plugs are black, signifying that either its running rich or the spark is not powerful enough. It has an aftermarket exhaust and the stock jets, apparently that will make it run lean and too hot which could burn the valves? So now I'm thinking about rejetting the carbs if the CDI doesn't work, thoughts?



Running list-----------------
Things I've done to it so far:
-Cleaned Carbs 4x (Jets cleaned, mixing screws adjusted, 100psi air blown through passages, diaphragms inspected, http://imgur.com/a/PgTDC)
-Cleaned and inspected airbox
-set valve lift adjustments
-synced carbs
-inspected timing
-replaced spark plugs
-checked gas tank
-cleaned gas tank petcock valve
-changed oil and filter
-replaced stock battery with 12A-A

Things to do:
-shim carb needles with #4 washers (planning on doing 2 washers, anyone have any suggestions?)
-get it to idle again and check the slide movement
-replace CDI

Possibilities:
-Rejet the carbs


Thanks for the help,
Alex.

[choneofakind]

To test the slides, the bike doesn't need to be running.

Try this:

Link to original page on YouTube.

notice how slowly the slides drop back down. If they're torn, the won't go up much, and they'll snap back down

[azwillnj]

Originally Posted by choneofakind

To test the slides, the bike doesn't need to be running.

Try this:

notice how slowly the slides drop back down. If they're torn, the won't go up much, and they'll snap back down

I'll give this a try when I get home this afternoon, but I'm pretty sure they're fine, I took them out and inspected them a couple times already..

Alex.

[n4mwd]

With problems like you describe, its a sure bet that the carbs are messed up somehow. Don't waste money on a new CDI or coils, that wont help. I have NEVER heard of those parts actually going bad on a Ninja 250.

On the Ninja carbs, there are multiple passageways (some hidden). Seems like most people miss one or two when cleaning them. Each and every one must be wired out.

Here is a video of the procedure:

Link to original page on YouTube.

If all else fails, I have an EFI kit I'm trying to unload.

[azwillnj]

Update:

Checked compression, Cyl 1 was 125psi and Cyl 2 was 155psi a 30 psi difference is substantial, but even 125psi should be enough to make it run.

Used compressed air to check the slide movement and they are operating just like the video above.

I currently have the carb in an ultrasonic parts washer that we have at work, going to leave it for about 2 hours, then put everything back together and hope that works.

I've been thinking about taking the head off and inspecting the valves.. thoughts?

Running list-----------------
Red=new item

Things I've done to it so far:
-Cleaned Carbs 4x (Jets cleaned, mixing screws adjusted, 100psi air blown through passages, diaphragms inspected, http://imgur.com/a/PgTDC)
-Cleaned and inspected airbox
-set valve lift adjustments
-synced carbs
-inspected timing
-replaced spark plugs
-replaced the coils
-checked gas tank
-cleaned gas tank petcock valve
-changed oil and filter
-replaced stock battery with 12A-A
-shimed carb needles with two #4 washers
-used compressed air to check the slide movement

Things to do:
-replace CDI (on the way, ordered from eBay)
-Reassemble carbs after 2 hours in ultrasonic parts washer

Possibilities:
-Rejet the carbs
-Remove head, inspect valves


I'm very quickly running out of ideas,
Alex.