What in Hades am I missing??

[gbyoung2]

New to this forum, so if this has been covered before please point me to the thread.

Working on a 2004 that needed the top end rebuilt (new pistons, cylinders honed, etc.). Reassembled everything according to the Manual but it just won't light off. Have checked, and rechecked the cam timing, and as best I can tell everything is spot on. Trying to start/run it using an auxiliary fuel supply. Have spark, have compression, but still no go. What in Hades am I missing.

I'm a semi-pro mechanic, so everything done to this bike is nothing new to me, but still... getting really frustrated. Really beginning to question the Manual procedure.

TIA

[CC Cowboy]

I'm no mechanic (but I have stayed at Holiday Inn before) but if you have spark and compression I would think it must be fuel that is missing.

[gbyoung2]

Originally Posted by CC Cowboy

I'm no mechanic (but I have stayed at Holiday Inn before) but if you have spark and compression I would think it must be fuel that is missing.

LOL!

Yeah, have stayed at a few of those myself when I was working as a Cat mechanic in years gone by.

With apologies to the owner who frequents this site, the drain screws on the carbs are so buggered up I can't get them out without pulling carbs themselves. What I have done is squirt raw gas down in the vacuum line for the petcock. Did manage to get it to sputter a few times, but it was a "wimpy" sputter and she never took off.

I am still questioning the procedure in the Manual itself. That whole cam timing and valve adjustment procedure is rather convoluted, IMHO. Has there been an errata issued regarding that Top End section??

[shiftdrift06]

How does the carbs look? If they been sitting they will most definitely need to be clean. and the gas in tank flushed.

http://faq.ninja250.org/wiki/General..._won%27t_start

Have you check you valves? Even though very small adjustment makes the biggest difference.

Make sure your battery fully charge. I had a weak battery would crank but the spark was weak. Kept it hooked on battery to get her running.

[greenaero]

Since you had the top end apart, check that your camshaft timing is correct.

[gbyoung2]

Originally Posted by greenaero

Since you had the top end apart, check that your camshaft timing is correct.

From my original post: "Have checked, and rechecked the cam timing, and as best I can tell everything is spot on."

[Motofool]

I am not aware of any problem with the manual.

Try a car battery and be gentle with your starter; your frustration may overheat it due to repetitive attempts.

Right after repair, compression should be low, making start ups difficult.

I would verify the intensity and timing of the sparks first.

As all mechanics are OK, I would focus on carburation next.
All passages and jets very clean and tight rubber boots and vacuum connections.

Next would be pushing start (find a down hill), so rpm's go high enough to improve compression and induce combustion.

Best

[gbyoung2]

Originally Posted by Motofool

I am not aware of any problem with the manual.

Try a car battery and be gentle with your starter; your frustration may overheat it due to repetitive attempts.

Right after repair, compression should be low, making start ups difficult.

I would verify the intensity and timing of the sparks first.

As all mechanics are OK, I would focus on carburation next.
All passages and jets very clean and tight rubber boots and vacuum connections.

Next would be pushing start (find a down hill), so rpm's go high enough to improve compression and induce combustion.

Best

Appreciate that, and will probably check spark timing first, altho' I have done nothing that would have altered that.

Battery charge is up there and spins the engine pretty good. Even with the bike's battery, I have been mindful of over-heating the starter. Getting access to a car battery is a thought. I do have a vehicle close to the garage that has a new one, so might give that a try.... again being mindful of extended crank times.

In a poke at myself: Have thought about the hill thingy. The first thought is that it would be terribly embarassing that anything coming out of this shop would require a "drastic" measure such as that. I think a couple of neighbor bikers that live on that hill would find that very amusing.

The second thought was that I'd have to push back up the hill should it not crank. Even as light as these bikes are, at my age that would be a PITA.

Seriously tho', think we'll check the spark timing first, then hit the carbs.

I am sure the owner is following this thread and is finding it most amusing.

FWIW - this is the reason why the top end needed rebuilt:

[gbyoung2]

#2 Cylinder Timing mark:


Exhaust Cam:


Intake Cam (pin 33 is right before the sprocket line):


Exhaust cam lobe:


Intake cam lobe:


Checked spark and timing with a light. All seem spot on.

Comments/suggestions please.

.

[Alex]

Guy - I bumped up the picture sizes in your post so people could see them directly here.

[gbyoung2]

Originally Posted by Alex

Guy - I bumped up the picture sizes in your post so people could see them directly here.

Thanks Alex.

Wasn't sure what proper protocol was on this forum, so I just posted thumbnails with links to the bigger pix. Some frown on taking up the additional bandwidth.

Guy

[flynjay]

Guy - Did you plug the vacuum line to the petcock?

If you have 33 joints between the marks then your timing is spot on. Also make sure your tensioner is installed correctly, it's bad if it's not (broken valves / intake rockers).

Other than that try to hook a fuel source to the carb inlet and plug the vacuum line. If you have compression and spark then remove the carbs and clean them.

I have found a pair of vice grips can get the carb drain plugs out.

[gbyoung2]

Originally Posted by flynjay

Guy - Did you plug the vacuum line to the petcock?

If you have 33 joints between the marks then your timing is spot on. Also make sure your tensioner is installed correctly, it's bad if it's not (broken valves / intake rockers).

Other than that try to hook a fuel source to the carb inlet and plug the vacuum line. If you have compression and spark then remove the carbs and clean them.

I have found a pair of vice grips can get the carb drain plugs out.

Yes, the vacuum line was plugged. Tensioner seems intact and doing it's job.

Fuel is coming from an auxiliary tank with fresh fuel, altho' the owner has said that he filled up just before the bike took a dump.

I did eventually get the bowl drains out, so I know fresh fuel is in there now.

Compression on both, newly rebuilt cylinders, cold, is right at 150. The "good" cylinder when the bike was hot pumped a little over 170.

I may have no option at this point but to do the "run it down the hill" trick.

Gawd, I hate to do that...............

[flynjay]

Originally Posted by gbyoung2

Yes, the vacuum line was plugged. Tensioner seems intact and doing it's job.

Fuel is coming from an auxiliary tank with fresh fuel, altho' the owner has said that he filled up just before the bike took a dump.

I did eventually get the bowl drains out, so I know fresh fuel is in there now.

Compression on both, newly rebuilt cylinders, cold, is right at 150. The "good" cylinder when the bike was hot pumped a little over 170.

I may have no option at this point but to do the "run it down the hill" trick.

Gawd, I hate to do that...............

Well you definately have compression. If you have spark and the plugs look good with the proper gap, then it is a fuel problem.

[gbyoung2]

Originally Posted by flynjay

Well you definately have compression. If you have spark and the plugs look good with the proper gap, then it is a fuel problem.

We'll figure it out, but it is definitively frustrating. In all the years I have fooling with bikes, I have NEVER had one as strange as this one before.

And apologies to those who don't play with such toys, the last option is to just take it behind the garage and put it out of its misery:

[choneofakind]

This may seem really dumb, but just suck a little extra on the vacuum line to make sure the bowls are filled. It always seems to take more sucking on the vacuum line that I expect before the first start-up of the season.

[gbyoung2]

Originally Posted by choneofakind

This may seem really dumb, but just suck a little extra on the vacuum line to make sure the bowls are filled. It always seems to take more sucking on the vacuum line that I expect before the first start-up of the season.

Again, running it off an auxiliary fuel supply, so no vacuum needed at this point:



.

[Motofool]

Did you check the actual level of the fuel inside each bowl?

You can do that with a U shape hose connected to the drains at the bottom of the bowls.

That feeder is perfect just like it is.

That damaged piston and that "performance" air filter make me suspect of a chronic lean mix condition.
It may need bigger jets, who knows?

There is tiny gas filter at the carbs inlet nipple, did you check that one?

[GeorgeRYoung]

Did you try starter fluid?

When I got my '89 EX250, the carbs were so clogged, starter fluid was the only way the seller could demonstrate that the motor ran.

In case it's carbs, there's an excellent carb cleaning how-to at http://faq.ninja250.org/wiki/How_do_...n_the_carbs%3F. I've recommended it to the Concours folk also.

[gbyoung2]

Originally Posted by Motofool

Did you check the actual level of the fuel inside each bowl?

You can do that with a U shape hose connected to the drains at the bottom of the bowls.

That feeder is perfect just like it is.

That damaged piston and that "performance" air filter make me suspect of a chronic lean mix condition.
It may need bigger jets, who knows?

There is tiny gas filter at the carbs inlet nipple, did you check that one?

Haven't checked fuel levels yet, but carb work begins in earnest today.

I also questioned the air filters when I found the holed piston, but the owner said that carbs had been rejetted.

We'll dig deeper a little later.

[gbyoung2]

Originally Posted by GeorgeRYoung

Did you try starter fluid?

When I got my '89 EX250, the carbs were so clogged, starter fluid was the only way the seller could demonstrate that the motor ran.

In case it's carbs, there's an excellent carb cleaning how-to at http://faq.ninja250.org/wiki/How_do_...n_the_carbs%3F. I've recommended it to the Concours folk also.

How you been George??

Nope, no ether yet. I tend to shy away from that stuff. Back in my old Cat days, I ran across a number of diesel engines where it was routinely used. Rather than get their glow plugs working, they just used ether. Over time, those engines became what were known as "Ether Babies." Even during the hot summer mos., using it was the only way you could get them started.

Appreciate the link. We'll take a looksee.

[gbyoung2]

and took a look at my (Smugmug) gallery stats.

The cam timing series took 39 hits (as of this a.m.). The holed piston shot took 181.

Many, many thanks to all that took a looksee.

[Jinx250]

It has to be the carbs. I've done my share of resurrections, and once I ruled out the electrical side, it always came down to the fuel delivery. Double check that the wires from the harness are solidly connected to the coils. I know it sounds simple and silly, but I had a buddy who just had a running issue that turned out to be the wire going to the coil not being connected.

[gbyoung2]

Originally Posted by Jinx250

It has to be the carbs. I've done my share of resurrections, and once I ruled out the electrical side, it always came down to the fuel delivery. Double check that the wires from the harness are solidly connected to the coils. I know it sounds simple and silly, but I had a buddy who just had a running issue that turned out to be the wire going to the coil not being connected.

Carbs are off now soaking, and will dig into them a little later today. Have to get some wheels swapped out on a Beemer that's also in here.

No rest for the weary.

[flynjay]

This does not have bearing on your current problem but....

What spark plugs are you running?

[gbyoung2]

Originally Posted by flynjay

This does not have bearing on your current problem but....

What spark plugs are you running?

It could, but I'm not sure at the moment. I did look at them and should have made a note what they were, but didn't. They're in the bike now, but will pull them out shortly and see.

[flynjay]

Originally Posted by gbyoung2

It could, but I'm not sure at the moment. I did look at them and should have made a note what they were, but didn't. They're in the bike now, but will pull them out shortly and see.

If they are champions, that might explain the hole in the piston.

I use NGK.

http://faq.ninja250.org/wiki/Changin...rands_to_avoid

[Alex]

Originally Posted by gbyoung2

and took a look at my (Smugmug) gallery stats.

The cam timing series took 39 hits (as of this a.m.). The holed piston shot took 181.

Many, many thanks to all that took a looksee.

This page is still pulling directly from the smugmug galleries (they are just live links), so every time that this thread is viewed, the stats go up on the smugmug side.

[gbyoung2]

Have used the line on the drain to check bowl fuel levels before, and did that on these prior to pulling the carbs. They were spot on.

Then the fun began when I started taking them apart. Many of the bowl screws were buggered up, but managed to break them free and got the bowls off.

Normally I pull the pilot jets first, but they were so tight they wouldn't budge, Decided to them pull the needle jet (tube) with main jets still attached. These too were extremely and needed to use a 6-point box wrench to get them free.

This is what I found on both carbs:









Considering the long ported shank on the pilot jets, I can only assume they are distorted too.

Then pulled the caps to check the diaphragms. This what I found on one of them:


Mixture idle needles looked okay and were both turned out an equal amount.

This is a case of being ham-fisted in all the wrong places.

[flynjay]

Well there's your problem....

I don't even know how that could happen.

[gbyoung2]

Originally Posted by flynjay

Well there's your problem....

I don't even know how that could happen.

Tightening the needle jet (with a wrench) against this piece waaay too much:

[flynjay]

How much are replacement parts going to cost?

If the diaphragms arn't salvagable, it might be easier to buy a set of used carbs.

[gbyoung2]

Originally Posted by flynjay

How much are replacement parts going to cost?

If the diaphragms arn't salvagable, it might be easier to buy a set of used carbs.

I have no idea what else may be damaged, and since I can't get the pilot jets out (yet, anyway), I'm going to make this recommendation to the owner. I've been dickin' around far too long as it is now. I also don't want to risk fookin' up the new top end rebuild and have it come back on me later due some wierd carb issue.

.

[el250]

Originally Posted by flynjay

Well there's your problem....

I don't even know how that could happen.

Pretty sure it is Skippii's bike....

[gbyoung2]

Originally Posted by el250

Pretty sure it is Skippii's bike....

Gotta laugh; give the man the Kewpie doll!!!

I just got off the phone with him about a half hour ago. He's seen/read the thread, but had NO IDEA his bike was the subject of my query.

Fortunately, he does have a set of carbs. Old, may be gummed up, but have to be danged sure better of what I found in the ones that came off his bike.

I can deal with gummed, but not distorted/bent needle jets.

He's gonna get them this w/e, and we'll go from there.

.

[Skippii]

Originally Posted by el250

Pretty sure it is Skippii's bike....

I can't believe someone noticed this before I did.
I'd read the first 10 posts or so on my phone (which didn't show pictures) but didn't have anything to suggest, then I never came back to it. Been busy at work lately where I tend do to a lot of my interwebbing...never even occurred to me y'all might be discussing my bike (which, btw, is a 2005, not a 2004...that's my defense!)

Anyway, back to the subject at hand....

These carbs were off my 2006 Ninja 250, which I'd spent hours carefully jetting with an exhaust gas analyzer. I'd replaced the main jets, shimmed the needles and adjusted the idle screws, but I never removed the needle slots--the parts which appear to be slightly butchered. I believe I was the second owner of that bike, and it had never been modified, so either they got that way on their own inside the carbs or they came from the factory like that--neither of which really seems likely. Anyway, after I got rid of that bike I kept the carbs and the K&N pods, and when I got the 2005 just stuck those carbs and pods on together.

Here's what confuses the heck out of me:
Those carbs have been on this bike in that condition for about 12,000 miles, and on the previous bike for 5,000 miles, and I've never had any problems with them.
The only time they were ever opened in the last 3 years was at the end of last year. I was doing a valve check/adjustment, and noticed that my engine seemed to be running a little rich, so while I was working on the engine, I asked my friend who was helping me with little things (mostly holding things, fetching me a drink, grabbing the appropriate allan wrench, etc) to check how many washers I'd used under the needles. He opened up the tops, counted the washers (I believe just one, IIRC) and I said to leave them as they were rather than risk going lean, and he closed them back up. I'm guessing he may have pinched the diaphragm a bit when he closed them...there was a very slight tear in one of them before, but nothing like in that picture.

So, the real question I have is this: if these carbs have worked flawlessly in this condition for the past 17,000 miles, why would it only make such a huge difference now with the new pistons installed?
Even the day after it broke down it still fired up almost immediately on one cylinder when I went back to check on it by the side of the road (for about 2 seconds--I hit the kill switch as soon as I saw the green coolant shoot out the left side.)

[gbyoung2]

Originally Posted by Skippii

Even the day after it broke down it still fired up almost immediately on one cylinder when I went back to check on it by the side of the road (for about 2 seconds--I hit the kill switch as soon as I saw the green coolant shoot out the left side.)

Skippii, that wasn't the case the very first time I fired it up in here after replacing the missing coolant line bolt and adding coolant - it took forever to eventually light off. Obviously running on one cylinder only, I ran it long enough to get a thermal scan of the pipes, then pulled the plugs and ran a compression check. When hot. the left cylinder pumped up to a little over 170; right side was zip. That's when we started to tear into it and found the holed piston.

It's just as much a mystery to me, which is why I initiated this thread to begin with. I wanted other eyes to check my work.

.

[Skippii]

Originally Posted by gbyoung2

Skippii, that wasn't the case the very first time I fired it up in here after replacing the missing coolant line bolt and adding coolant - it took forever to eventually light off. Obviously running on one cylinder only, I ran it long enough to get a thermal scan of the pipes, then pulled the plugs and ran a compression check. When hot. the left cylinder pumped up to a little over 170; right side was zip. That's when we started to tear into it and found the holed piston.

It's just as much a mystery to me, which is why I initiated this thread to begin with. I wanted other eyes to check my work.

.

I'm just worried that if the spare carbs don't work, the bike will be taken out back and shot.

In all seriousness, I was originally thinking about doing all the work myself...I'm VERY glad I didn't do that--It's comforting to know someone with a lot more experience is tackling the project.
I'm heading over to pick up the carbs on Monday (my 'weekend') and I'll drop them off on my way to work Wednesday.

[gbyoung2]

Originally Posted by Skippii

I'm just worried that if the spare carbs don't work, the bike will be taken out back and shot.

In all seriousness, I was originally thinking about doing all the work myself...I'm VERY glad I didn't do that--It's comforting to know someone with a lot more experience is tackling the project.
I'm heading over to pick up the carbs on Monday (my 'weekend') and I'll drop them off on my way to work Wednesday.

LOL! I'll let you do the honors.

Looking forward to getting them. And yes, I'm a little nervous too, but think we have all the bases covered and enough folks have eyed where things are now to have spotted something that may be amiss.

.

[Skippii]

Originally Posted by gbyoung2

something that may be amiss.

Well, I don't think there's any question that there's something amiss with those carbs!