Cleaned Carbs, Replaced Gas, Still having engine problems.

[choneofakind]

hmmm sounds like you've done everything I would ever think of doing.

Just make sure to fill the float bowls completely, and then play with varying degrees of choke/throttle. It might sputter through the thirst couple fires like mine did yesterday night, but then when it did start, it roared to life and blew a big black cloud of unburnt fuel out the pipes from the choke I just used. Anyhow, my point is sometimes they're cranky starting. You've done the work, I'm rooting for your bike to run!!!

If it honestly won't start after this, I guess inspecting the valves would be the logical next step, but that seems kinda extreme for a bike that only has 14k on it. I wouldn't expect those valves to be damaged. Maybe they were tight if the PO didn't adjust the valves, but it seems early for hardcore damage to the valves.

[cbdallas]

Have you checked the level in the float bowls? That turned out to be the problem with my 1994 that ran fine cold, but ran very badly when hot. My bowls were overfilling, but not overflowing. Ran great until I got about halfway to work, then the bad behavior started. Let it sit & cool completely off, & it would run great.

[azwillnj]

Originally Posted by cbdallas

Have you checked the level in the float bowls? That turned out to be the problem with my 1994 that ran fine cold, but ran very badly when hot. My bowls were overfilling, but not overflowing. Ran great until I got about halfway to work, then the bad behavior started. Let it sit & cool completely off, & it would run great.

I had checked them before and they were 17mm, the spec is (17mm +/- 2mm) because of the charred plugs I adjusted the bowls to 18mm yesterday so the bowls would fill less.

[n4mwd]

Are you absolutely certain you adjusted the valves properly?

The differing compression says that the valves aren't adjusted like they should be. There are other things that can cause that, but they are not likely on an engine with that few miles on it.

Make sure you don't over torque the set screws or else you can destroy the engine.

Adjust the valves on Cyl #1 at TDC and then double check to make sure the screws didn't rotate when you tighten the nut. Rotate the crank to cyl #2 and do those. There are multiple marks on the flywheel so make sure you are using the right one. Don't try to wing it and adjust them without using the crank marks.

But having said all that, the problem with it not running right is still likely to be the carbs. I doubt your new CDI will help. I don't think ultrasonic cleaning will help much. You have to wire out the passageways. I think there are 4 per carb if I remember correctly.

Maybe take the carb to a professional Ninja shop and ask them to look at it. Another option is to buy a used one off ebay. They tend to run about $250 but I've seen them go for $50.

Lastly, on the CDI, not all of them are compatable. Some of the pre-95 modules have the wires backwards from the 2007 module. Just be aware of that so you don't short out what's left of the bike with an older module.

[azwillnj]

Just reassembled the carbs, they look incredible, not a spec of dirt anywhere, I still have not wired anything out as I have heard from several sources that if you scratch the jets or passageways it will cause it to not run correctly (although it doesn't run correctly now so I don't really have much to lose). Light passes through the jets and other passageways just fine and all the holes look round. I am going to try to run it one more time with the new and old CDI boxes, then if all else fails I will wire the passages out.

We adjusted on the lower end of the valve tolerance assuming they would loosen as the time went on, and we double checked. I assume we did something wrong as the compression is different on both of them, If I can't get it to run I'll take it apart again and check them again.

Also, the CDI is from my year, 2007.. http://www.ebay.com/itm/370594573628...#ht_634wt_1344



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
-Ultrasonically soaked/cleaned carb body, jets, and mixture screws for 4 hours.

Things to do:
-replace CDI (on the way, ordered from eBay)

Possibilities:
-Rejet the carbs
-Remove head, inspect valves
-Remove valve cover, re-inspect valve lift
-Wire out all carb passageways

[greg737]

quite a while back in this thread you were asking about "the other fuel filter". I don't think anyone ever pointed out where it is. The best picture of its location is in this FAQ entry: http://faq.ninja250.org/wiki/How_do_...fuel_filter%3F

It is press-fit into the metal tube on the side of the carbs where the rubber fuel tube from the petcock connects.

[alex.s]

try checking the charging system. check the input and output of the VRR. if the VRR is bad it can send the wrong voltage to the CDI which will screw with it. if the voltage is high you'll burn the CDI. if its low, you wont get proper spark at higher RPM. another possibility; i easily could be wrong on this but i believe the 250s use electrical timing with a hall sensor on the stator. theres a woodruff key to set/offset the timing. if your pickup sensor is going out, or loose, or the key is gone, you will have a very hard time running. if the pickup sensor is simply loose, it will move around and running will come and go. metal heating up expands right? so i would think it would get tighter as it warmed up, but i donno. just suggestions.

if you use soft material like wood to clean the jets, you wont screw them up


if you take the spark plug out and connect it to the coil, you can hold it against the ground and you should see spark. if it doesn't, well...

[greg737]

It has been my experience that when a bike idles fine but dies the moment you touch the throttle it is because it is too rich. The fact that your plugs keep coming out of the engine all black colored backs up this theory.

You are probably really, really close to having a fully functional bike. You just have to solve this over-rich problem. I'm willing to bet it's idling way rich, absolutely balanced on the ragged edge of being able to operate at all. The moment you add any throttle the extra fuel causes the incoming mixture to become too rich to burn. If you can get the idle set a bit leaner you'll probably be able to get it run.

You mentioned that the prior owner put an aftermarket pipe on the bike so my bet is he also made some change(s) to rich up the mixture: Did he change the needles? The stock needles are brass while most aftermarkets needles are steel. If he didn't change the needles did he add a bunch of washers to the stock needle? If the needles are aftermarket models were is the clip installed?

Bottom line, it's highly likely the whole issue is just a simple air/fuel ratio problem.

[CynicalC]

^^^ listen to this guy. Also forget the ultrasonic cleaning. Do it by hand and you'll be absolutely sure it's done right. If your plugs are black, the bike is idling rich. There's your starting point. Clean the plugs, adjust the idle mixture. Run it and check the plugs again.

[n4mwd]

If you use copper wire to clear out the passages then there is very little chance you will damage anything. Use steel mig wire when the copper wont go through. If you are careful, the chances of burrowing an extra hole in your carb is slim.

The valves on a Ninja get tighter as they wear. So if you adjusted them on the tight side, they will only get tighter - not looser. A valve adjustment error is the most probable cause of a significant difference in compression between the two cylinders (assuming that there was no gauge error).

Also, another error is over-torquing the valve adjusting nuts - which can destroy the engine. If you open it up again, you need to try to inspect the rocker arms to see if there are any cracks or chips. These break with too much torque. Then they slip out and that valve no longer works. Worst case, the broken pieces cause the timing chain to skip a tooth which causes an impact between all valves and pistons. That effectively destroys the engine.

Once you get things going, I suggest adding a small inline fuel filter between the petcock and the carb. The stock filter (located at the fuel inlet to the carb) is just a little screen and is not all that great. However, most of the time that they get clogged up, its because they have been sitting too much.

[azwillnj]

It wont even idle now.. It just backfires. What the hell do I do now?

The stator is the only thing left.

[n4mwd]

Originally Posted by azwillnj

It wont even idle now.. It just backfires. What the hell do I do now?

The stator is the only thing left.

What did you do between the last time it ran and now?

I doubt that its an electrical problem, but I know that on some bikes the wiring to the coils can go bad at the connectors. Try inspecting the wires and connectors that attach to the coils.

I assume the new CDI made no difference.

I have never heard of a CDI ignition pickup coil ever going bad on a Ninja. I assume that's what you meant by 'stator'.

[azwillnj]

The only thing I have done since last idle is ultrasonically clean the carbs and cut the battery box off the airbox (I didn't miss, the airbox still has 100% integrity).. With both the new (from ebay) and the old CDI it does the same thing..

This is what I was talking about with the stator: http://www.ebay.com/itm/170818170253...#ht_500wt_1361

Alex.

[Asspire]

tried checking for high resistance in the plug wires? will cause the problem to get worse with higher temps, and will cause it to misfire/stall. if it idles and dies as soon as the engine is loaded then that might be the cause. plus I don't see it on your list o parts replaced.

good luck

[n4mwd]

Originally Posted by azwillnj

The only thing I have done since last idle is ultrasonically clean the carbs and cut the battery box off the airbox (I didn't miss, the airbox still has 100% integrity).. With both the new (from ebay) and the old CDI it does the same thing..

This is what I was talking about with the stator: http://www.ebay.com/itm/170818170253...#ht_500wt_1361

Alex.

The stator is the alternator. I think the CDI pickup coil is in the same housing, but is not the same thing. In any event, changing it is not likely to make a difference.

Try buying a working carburetor off ebay. That should get you going.

[azwillnj]

Originally Posted by n4mwd

The stator is the alternator. I think the CDI pickup coil is in the same housing, but is not the same thing. In any event, changing it is not likely to make a difference.

Try buying a working carburetor off ebay. That should get you going.

I really can't see how it could be the carb, its spotless... completely spotless, it looks like a new carb.

[n4mwd]

Originally Posted by azwillnj

I really can't see how it could be the carb, its spotless... completely spotless, it looks like a new carb.

If you didn't wire it out, you didn't clean it.

[azwillnj]

Originally Posted by n4mwd

If you didn't wire it out, you didn't clean it.

It's like a broken record in this thread.. I used an ultrasonic cleaning bath designed to get hundreds of thousands of miles of gunk off a piston from a commercial diesel engine. They had just changed solvent and I left the carb body inside for double what they usually do with the pistons.. It's not the carbs!

Lets make a deal n4mwd.. I'll take the carbs off the bike, for the fifth time, and wire them out.. if they don't work you sell me the EFI kit for $400, shipped... I'll even video the process to prove the point.. Deal?

Alex.

[choneofakind]

You adjusted the valves to the tight side of spec? That's contributing to having a hard time starting. The valves on the 250 get tighter with miles, not looser. The bike is also loads easier to start with the valves on the looser side of spec.

http://faq.ninja250.org/wiki/Why_do_...be_adjusted%3F

[azwillnj]

Originally Posted by choneofakind

You adjusted the valves to the tight side of spec? That's contributing to having a hard time starting. The valves on the 250 get tighter with miles, not looser. The bike is also loads easier to start with the valves on the looser side of spec.

http://faq.ninja250.org/wiki/Why_do_...be_adjusted%3F

Just to clarify; when spacing the valves, I used the smaller of the 2 feeler gauges in the spec.. this in turn should cause a larger valve opening.

[CZroe]

Originally Posted by azwillnj

Just to clarify; when spacing the valves, I used the smaller of the 2 feeler gauges in the spec.. this in turn should cause a larger valve opening.

No it wouldn't. The larger one measures a larger space for a looser spec.

[azwillnj]

Originally Posted by CZroe

No it wouldn't. The larger one measures a larger space for a looser spec.

If the spacing between the cam and the lifter is smaller, the cam will contact the lifter sooner, and lift more. That's how I adjusted it.

[CZroe]

Originally Posted by azwillnj

If the spacing between the cam and the lifter is smaller, the cam will contact the lifter sooner, and lift more. That's how I adjusted it.

Contact is contact. If there is no bending or flexing after contact (and there shouldn't be), the lifting height is the same regardless. My understanding is that we're worried about it not having enough clearance before then so that it doesn't damage anything when it goes through the lifting part of the cycle.

[choneofakind]

no, when they're tight, there's less clearance. By using the thinner feeler gauge, you made your valves on the tighter side of spec.

When I adjusted mine, they were all unable to fit the thinnest feeler I had that was still in spec. I opened them up to the thicker side of spec and it starts loads easier. Everywhere I've read says that people's valves get less clearance with miles.

[azwillnj]

Originally Posted by CZroe

Contact is contact. If there is no bending or flexing after contact (and there shouldn't be), the lifting height is the same regardless. My understanding is that we're worried about it not having enough clearance before then so that it doesn't damage anything when it goes through the lifting part of the cycle.

That's wrong, lifting height is directly related to rocker arm/cam lobe clearance. If you adjust the clearance to be closer to the cam it will contact sooner and push the rocker arm down more, this will push the valve open more, it's one connected unit.

[n4mwd]

Ultrasonic cleaning didn't do anything but make them shiny and stop working altogether. Is that a fair summary? Its time to wire it out and get it back on the road.

It sounds like you have access to a shop so you can also inspect the piston faces with a fiberscope to see if there is any damage. Not likely, but its not something to ignore if you have the equipment to do it.

The difference in compression usually means that you either measured it wrong or your valves are off somehow. A differing compression like you mentioned is frequently caused by adjusting one or both cylinders on the wrong mark.

Chris is right and you should readjust your valves to be on the thicker/wider side. That is, use the thicker feeler guages. While you are in there, you need to carefully inspect the rockers to make sure you haven't damaged any by overtorqing the nuts. See if you can push them out when they aren't under tension. That's how you tell the broken ones.

There have been more than a few guys destroy their Ninja engines by overtorqing the valve adjusting nuts. Don't take this warning lightly. But if you do, you can buy new engines on ebay for about $500.

$400 for my EFI kit? You're getting warmer. You'll have to wait now because ecotrons just announced that he will be releasing a new throttle body in three weeks. If its any good, I may keep it now. You should have gotten it before he made that announcement.

[azwillnj]

Originally Posted by n4mwd

Ultrasonic cleaning didn't do anything but make them shiny and stop working altogether. Is that a fair summary? Its time to wire it out and get it back on the road.

I didn't shine up the outside, the solvent got into places your wires could have never reached, and the ultrasonics and the heat should have dislodged every piece of foreign matter on it... That combined with the through rinsing, and blowing out with compressed air after the ultrasonic bath left them completely spotless.

Because I have no other options at this point, what is your process for wiring them out, what gauge wires do you use, and where do you put them?

Alex.

[dale-j]

Sounds an awful lot like fuel issues to me. What are you running for float height? Given the bogging and black plugs I would have guessed that one of your pilot or idle air passages was plugged in the carb body (similar symptoms to my wife's bike before the third, full body carb cleaning) however given the ultrasonic cleaning (I disassembled and soaked for a week in a gallon paint can of gas with a bottle of seafoam, and blew out - so what you did was more thorough from the sounds of it) the only other thing I can think of is that your fuel level is too high. IIRC you should be running 14mm or so, and you can check it with a digital vernier caliper that has the plunge measurement on the opposite end.

S

[TnNinjaGirl]

Have the diaphragms been damaged? Any pinholes, are they seated correctly, are they pliable? All of the plastic in them is ok?

[azwillnj]

Originally Posted by dale-j

Sounds an awful lot like fuel issues to me. What are you running for float height? Given the bogging and black plugs I would have guessed that one of your pilot or idle air passages was plugged in the carb body (similar symptoms to my wife's bike before the third, full body carb cleaning) however given the ultrasonic cleaning (I disassembled and soaked for a week in a gallon paint can of gas with a bottle of seafoam, and blew out - so what you did was more thorough from the sounds of it) the only other thing I can think of is that your fuel level is too high. IIRC you should be running 14mm or so, and you can check it with a digital vernier caliper that has the plunge measurement on the opposite end.

S

I set the floats to 18mm, the spec is 17mm +-2mm I went with 18mm because I felt as though it was running too rich and that number is in spec and will fill the bowls less.

Have the diaphragms been damaged? Any pinholes, are they seated correctly, are they pliable? All of the plastic in them is ok?

Diaphragms are perfect, seated properly and react exactly as desired when using compressed air to simulate the engine revving.

[TnNinjaGirl]

It's just bizarre that it ran, and then stopped running. Like it had fuel in the bowls and then ran out and hasn't run right ever since.

When you open the throttle plates you can see fuel spraying? (can you do that on these carbs?) Anyways, is there absolute verification that the motor is actually getting fuel?

You say you are getting spark?

I would think even if the valves were a little too tight it would still run. Maybe not very well, but it should still get enough compression to sputter about.

[n4mwd]

Originally Posted by azwillnj

Because I have no other options at this point, what is your process for wiring them out, what gauge wires do you use, and where do you put them?

Alex.

Play the video I posted early on about how a carb is rebuilt. The guy in the video shows the process. If I remember correctly, there are 4 passages per carb that must be clear.

And as the other guy just said, you need everything adjusted properly as well.

[EMSRacer07]

as everyone has said ur valves are too tight. Another reason ur running rich, no air can come in. you have to put them pretty loose, meaning use a thicker guages not thinner. my bike wouldnt start for the longest time till i loosened the valves. they were really tight.

[greg737]

It really does sound like you added a whole new issue to the original problem when you did the valve adjustment. That's why the situation feels so confusing.

By the way, what do the carb's needles look like? Are they stock (brass, without clip-rings) or aftermarket (usually steel, with multiple clip-ring levels)? If they're stock, were there any washers under them? If they're aftermarket, what level was the clip at?

But before anything else you should resolve your valve adjustment confusion. Take a look at this how-to FAQ entry: http://faq.ninja250.org/wiki/What_is...t_procedure%3F

Then maybe you'll be down to dealing with a single issue type of problem.

[azwillnj]

I changed the valves to the larger end of the tolerance, apparently I missed one or it moved out of spec from the last time.. maybe from the back fires?

Anyway.. it fired right up and idled just fine.. responded cold, when it got warm it had almost the same response as before.. BUT.. If I slam the throttle and fight it with the choke I can get it up and past 4000 rpm and it responds fine up to red line until you let it go.

I am going to adjust the mixing screws tomorrow to try to get the idle to smooth out and allow it to get past that middle stage. I'm also going to pull the plugs before I do anything and see what they say.. I cleaned them before putting them back in.

As far as the needles, they are the stock needles, but I shimmed them with 2 #4 washers each totaling 1.4mm in shim.. I read in a few places this will help with response over 4k.. should I have not done that?

Alex.

[TnNinjaGirl]

WOO HOO!!! Progress!!!!

[azwillnj]

Originally Posted by TnNinjaGirl

WOO HOO!!! Progress!!!!

That's pretty much what I said.. it was about the first time I didn't envision kicking it over 300 spartan style haha.

[greg737]

Sounds like progress to me. I think you're back to just having a simple carb adjustment problem now.

Things to consider: Your problem may be symetrical (a symptom of both carbs) or it may be asymetrical to some degree. The problem could be a simple mixture (air/fuel ratio) problem or it could be a mixture problem that is made worse by an out-of-sync problem. Or there could be a vacuum leak on one of the cylinders which has happened to guys when they've pulled and replaced their carbs numerous times (occasionally a carb-to-engine boot gets put back on reversed, they're actually marked with "engine" and "carb" because it's very important in preventing vacuum leaks).

As soon as you can you should work on making sure the carbs are synchronized.

Good luck, hope the improvement continues.

[azwillnj]

Should I play with the mixing screws or sync first?

[greg737]

Originally Posted by azwillnj

Should I play with the mixing screws or sync first?

I'd say you should set the idle mixture screws first, just blindly set them to the rule-of-thumb 2 and 1/4, then if the bike will idle and throttle anything even close to normal do the sync, then do the more advanced idle mixture setting procedure FAQ http://http://faq.ninja250.org/wiki/...dle_mixture%3F, then sync it again, because as you will see the FAQ on setting the idle mixture assumes you've already synchronized the carbs. But you've got to start somewhere, right?

But it's altogether possible that your as yet unidentified carb problem might stop you from doing either the idle mixture screws or the sync. Both of those procedures assume you have a bike that will start, run well enough to get thoroughly warmed up and that it will respond to normal throttle blips without dieing.

I know you don't want to hear it but from your description about having to "slam" the throttle while playing the choke it still seems like you just might have a blocked passageway in one or both of the carbs. The evidence pointing to this is that when you have to do something as extreme as slam-and-choke to get it to rev up you're essentially creating a "work around" solution to compensate for an unresolved air/fuel mixture or delivery problem, getting the engine up through a rev range that would normally be aided and/or controlled by a particular passageway which isn't funtioning properly at the moment (in one or both of the carbs).