Failed Emissions test- CO was too high. What now?

[Fausto]

I am not exactly new here, I have lurked and learned from all of you for the past 4 months.

I got my first motorcycle a 2007 GZ250 with 4,447 miles. It did not start, battery was dead. I jumped it with out turning the car on and it started. But it could only idle. As soon as I pulled the throttle it would die. Came to the forum and read a lot. Tried the Sea foam like many recommended and drove it around for 15 miles on idle, while doing so I practiced in a parking lot at idle speeds. Cornering and braking, well anyways we felt like one, me and my new acquired bike. but it didn't work,

I came back to the forums and read a post with pictures about doing some mods to your bike and it included changing the needles. forgive me I dont remember the name but it helped. I removed the carb, pulled the needles and cleaned them. They were clogged bad with a tar like substance. Replaced the carb and connected everything back and it ran fine. Bought a new battery and charged it overnight and drove it to emissions today. But it failed. It said my CO carbon monoxide failed. Said my Idle standard should be 5.50 and I was at 9.51.

Could it be that the Sea Foam is affecting the reading or did I miss some carb adjustments?

Thanks for all your help.

[PimpS]

Fausto, sea foam, as far as my knowledge, should lower the emisions of CO, cause it makes burning better... Maybe your engine is just too lean? In any case, other much more skilled guys will guide you through and get your bike done and emisions right!
Take care, I hope for speedy solution!

[Fausto]

PimpS, thanks for the reply. I have a tank full of gas and I poured half a bottle of sea foam in it. So I am relieved I wont need to dispose of the gas or run it for another 200 miles.
So I would need to adjust something or alter the other to compensate?

[Fausto]

Can someone else help please. If my fuel mixture is too rich, what adjustments can I make to my carb? Can I counter act the richness by giving it more air. I have a stock air filter, do I remove the piece that restricts air? Anything?

[blaine]

Can someone else help please. If my fuel mixture is too rich, what adjustments can I make to my carb? Can I counter act the richness by giving it more air. I have a stock air filter, do I remove the piece that restricts air? Anything?
If you are running rich you can lean the mixture by adjusting the idle mixture,(pilot jet).You may need to remove the factory plug if it still in place.
:) :cool:

[Fausto]

Thank you Blain, very much. I think I remember reading about the the idle mixture screw. I do have a plug so I would have to drill it out. I'll search the forum for more info on drilling the plug.
I do have one question though. How will I know when I have the right mixture? At least till I pass the emissions test.
Thanks again!

[blaine]

Thank you Blain, very much. I think I remember reading about the the idle mixture screw. I do have a plug so I would have to drill it out. I'll search the forum for more info on drilling the plug.
I do have one question though. How will I know when I have the right mixture? At least till I pass the emissions test.
Thanks again!
2 1/2 turns out is a good starting point.You need to adjust with bike warmed up idling.Turn out slowly (rich) till the idle starts to roll,than back in (lean) till idle starts to stumble.About half way between both extremes,to were the bike idles smoothest.You may want to stay on the lean side till you pass emissions than adjust for smoothest idle.
:) :2tup:

[Fausto]

Ok, I get what happend. When I cleaned out the jets it and replaced them I remember turning the pilot jet in all the way. So it is seated and I did not count the turns. Does anyone know what the stock number of turns of from the seated position?

[blaine]

Ok, I get what happend. When I cleaned out the jets it and replaced them I remember turning the pilot jet in all the way. So it is seated and I did not count the turns. Does anyone know what the stock number of turns of from the seated position?
2.5 turns from seated. :) :cool:

[Fausto]

Thanks for the info, I'll get it done when I get off work in a few hours. But I am confused Blain, I thought the Pilot Scew was underneath the carb under the float chamber? I thought I would have to dissasmble the carb. I was looking at the diagram for the carb in the owners manual and the pilot screw was #10 on the list. :??:

[Fausto]

Ok I found an example of the Pilot screw here viewtopic.php?f=8&t=617 (http://www.gz250bike.com/forum/viewtopic.php?f=8&t=617)
And it is the picture of the pilot screw. So the pilot jet that is underneath the float chamber is not related here? Should I adjust it, or does that one seat in completely?
Thanks for your help here guys.

[blaine]

The pilot screw Adjustment is # 13.It is located beside the float bowel.
:) :cool:

[Fausto]

Got it! Ok here is the deal, I realized the carb was not secured properly. I failed to tighten the the rings that secure the carb to the air box and to the motor. I still went ahead and drilled through to get access to the pilot screw. I turned it clockwise and seated. Then gave it 2 turns counter clock wise.The problem I am having is that it idles high until I give it throttle, it then goes down to a putter. I went another turn clockwise and it idles high and then it goes down to a putter. It doesn't seem to make a difference.
The bike was hot, I drove it around the block and 1/4 mile on the freeway. Its AZ so the temps are above 100 right now. What an I doing wrong? :retard:

[blaine]

Sounds like you may still have a vacuum leak.A easy way to check is to spray WD-40 around the boots & hoses with the bike running.If the idle increases you found your leak.
:) :cool:

[raul10141964]

If you do any mod to the carb retun it to the factory seting

[mrlmd1]

The dose of Seafoam should be 1-2 oz./gal of gas. Half a can for 3 gal of gas is an overdose and may be a cause of the bike running like crap or having the emissions off. Use up that tank of gas and then just put in regular gas, you don't need Seafoam with every tankful.

[Fausto]

@blain, I sprayed wd-40 and it didnt change. I drove it to work a couple times, and it ran ok. It would back fire when I turned it off every time. On the third day of driving it to work, it turned off on me while going 75 mph on the highway, I coasted to the side and it wouldn't turn on. Sounded like it had no gas. I switched the petcock to prime and it ran fine. What does that mean?

@raul, I haven't done any mods to the carb. I cleaned the jets and replaced them. Did I miss n adjustment some where?

@mrlmd1, ths the first time I added seafoam. Thanks for tha advice, I'll use it up and replenish with fresh gas.

[alantf]

I switched the petcock to prime and it ran fine. What does that mean?

Sounds like you're not getting the vacuum that's needed to open the petcock in "run" & "reserve" ("prime" doesn't need a vacuum) Check the vacuum pipe that goes from the engine to the petcock for splits & tightness. :)

[Fausto]

I switched the petcock to prime and it ran fine. What does that mean?

Sounds like you're not getting the vacuum that's needed to open the petcock in "run" & "reserve" ("prime" doesn't need a vacuum) Check the vacuum pipe that goes from the engine to the petcock for splits & tightness. :)

Thank you alantf-

I checked the hose and it looks fine. Is there another vacume hose? I read in a different post on a similare problem and someone mentioned an "S" hose form the crank case to the filter box? I havnt checked it yet but when I do I will, could that be affecting it too?

Thank you all again for your help. I hate that I am having all these questions and answers without any resolution, but I know I will be able to look back on this and be thankful for the learning experince

[Water Warrior 2]

I switched the petcock to prime and it ran fine. What does that mean?

Sounds like you're not getting the vacuum that's needed to open the petcock in "run" & "reserve" ("prime" doesn't need a vacuum) Check the vacuum pipe that goes from the engine to the petcock for splits & tightness. :)

Thank you alantf-

I checked the hose and it looks fine. Is there another vacume hose? I read in a different post on a similare problem and someone mentioned an "S" hose form the crank case to the filter box? I havnt checked it yet but when I do I will, could that be affecting it too?

Thank you all again for your help. I hate that I am having all these questions and answers without any resolution, but I know I will be able to look back on this and be thankful for the learning experince
And then it will be your turn to impart wisdom and experience to the next new member. For a smaller forum this one is just chalk full of info and helpful folks.

[Fausto]

Hey folks, here is an update.
I replaced the vacume hose and tiny clamps. Installed inline filter. Sprayed hoses with WD-40 while running and noticed no difference in sound. While the GZ was running I switched the petcock to run and a few min later it turned off and I noticed the fuel filter was dry.
I found the other vacume hose that runs down from the air box. Should that have a cap at the end? Cause it does.
I dont know what to do next. Is it my petcock that is bad?

[jonathan180iq]

The standard GZ petcock shouldn't have an OFF, IIRC. PRI-RUN-RES should be what you see.
If it's not running on RUN, then you have a vacuum problem. Even if you can get it started on PRI, which is straight flow, it won't last long because there isn't enough propert vacuum from the engine to the carb sucking gas down as needed. It sounds like someone previously replaced the petcock trying to sort this mess out. I would just order a factory petcock (or maybe send us a picture of what you have) and redo the whole thing. You're talking about a very simple install, 2 vacuum hoses and a gas line.

Oh, and ...If the fuel filter was dry and the bike was running, then you have put the fuel filter on the wrong hose. I can't really see any other way that could happen. Even with using PRI to get it started, you should have seen the fuel flowing and filling that thing up after the float bowl was filled.

I have seen people put filters on a vacuum hose before and never even know it.

The hose from the bottom of the air box should have a cap on it, yes.
It's a drain for junk that gets in there. Pull the plug every now and then to keep it clean. If you've never done that, then give it a whirl.

[Fausto]

The standard GZ petcock shouldn't have an OFF, IIRC. PRI-RUN-RES should be what you see.
If it's not running on RUN, then you have a vacuum problem. Even if you can get it started on PRI, which is straight flow, it won't last long because there isn't enough propert vacuum from the engine to the carb sucking gas down as needed. It sounds like someone previously replaced the petcock trying to sort this mess out. I would just order a factory petcock (or maybe send us a picture of what you have) and redo the whole thing. You're talking about a very simple install, 2 vacuum hoses and a gas line.

Oh, and ...If the fuel filter was dry and the bike was running, then you have put the fuel filter on the wrong hose. I can't really see any other way that could happen. Even with using PRI to get it started, you should have seen the fuel flowing and filling that thing up after the float bowl was filled.

I have seen people put filters on a vacuum hose before and never even know it.

The hose from the bottom of the air box should have a cap on it, yes.
It's a drain for junk that gets in there. Pull the plug every now and then to keep it clean. If you've never done that, then give it a whirl.

jonathan180iq, you missunderstood what I said completely. The GZ quit running after a few minutes of running in the "run" postition on the petcock. The inline fuel filter has an arrow that indicates in which direction the fuel runs. When in the prime position the fuel filter fills up with fuel, so there is no possible way the fuel filter is connected to the vacume line. I kindly thank you for trying to help.
I will drain out the hose from the air box.
Now that the lines have been replaced and tested what is next? Replacing the petcock or rebuilding it?

[Way]

I'm not an expert by any means but I suppose that's never stopped anyone from commenting. :tongue:

In looking over your posts, let's see if we can't at least follow what's been done:

1. it would only idle, would die when throttle applied

2. Pulled carb, cleaned needles. Clogged with tar-like substance

3. Ran fine, failed emissions

4. Had to tighten carb as it was not secured properly.

5. Adjusted pilot jet. Had more problems after.

You are still having a fuel flow problem it appears. The bike runs fine in the prime position correct? That means that the fuel filter is pointing in the right direction. So the filter should be fine.

You sprayed WD-40 on the vacuum hoses and nothing happened. The vacuum hoses should be fine. The petcock may or may not be bad but you haven't necessarily isolated that as the cause yet. The fact that you get flow in prime shows there's flow through the orifice.

You may still have a vacuum leak at the carb base.

You cleaned the carb but then found it hadn't been secured properly.

What is the condition of the carb gasket? I've never taken off the vacuum hose from the crankcase but how did it look inside the end where it enters the engine? If you had a tar-like substance in the carb, maybe you had some at the other end where the vacuum tube enters the motor? It sure sounds like you still have gunk somewhere. Nothing floating around in the gas tank?

Just some thoughts to help you. Hope you get it straightened out.

[jonathan180iq]

Thanks for the clarification. Re-reading it, I see my mistake.

The major point still stands though, which I think you got. There is an issue with vacuum not pulling gas in RUN.
If a replacement petcock is cheap, I would save yourself the hassle and just slap a new one on there.

A complete one is $81 from Ronayers.

[Fausto]

Way & Jonathan- thank you so much for your help.

I'll remove the carb check the gasket and dissasemble the petcock. I'll let you guys know how it turns out.
Maybe include pix if I get a chance. Thank you again!

[Way]

No problem friend, hope it works out to be something easy and cheap for you.

I was kind of looking around online and saw a suggestion where someone said to attach a piece of tubing to the vacuum fitting on the back of the petcock and apply suction to it. The fuel outlet of course going into a cup. If you get flow while applying suction then you have a vacuum problem. If not, the petcock is bad. Have you tried both the "run" and "reserve" positions? If it runs on reserve but not on run, you may have some gunk in there. I hate to see you throw parts at the problem if it's something that can be fixed cheap. I guess I fixated on the tar issue. :retard:

[Fausto]

No problem friend, hope it works out to be something easy and cheap for you.

I was kind of looking around online and saw a suggestion where someone said to attach a piece of tubing to the vacuum fitting on the back of the petcock and apply suction to it. The fuel outlet of course going into a cup. If you get flow while applying suction then you have a vacuum problem. If not, the petcock is bad. Have you tried both the "run" and "reserve" positions? If it runs on reserve but not on run, you may have some gunk in there. I hate to see you throw parts at the problem if it's something that can be fixed cheap. I guess I fixated on the tar issue. :retard:

Thanks Wayne, I'll definitley try that. It sounds way easier than removing the and dissambling the carb again. This will eliminate the possiblity of the petcock being bad before dissambling it. I appreciate your fixation on the gunk...lol- It is something I should have considered.
I will be working on it this weekend so I'll report back again. Thanks again. :)

[Fausto]

Here is my progress- Checked the petcock by placing it on run and applying suctions with a hose. The gas flowed freely, issue is not with the petcock. I replaced the vacuum hose that goes from the carb to the petcock, used a small zip tie instead of the wire type clamp. And that seemed to fix that issue. The bike can run all day with the petcock set to run or reserve.
Next issue is, which was the original issue, passing emissions. I started by removing the carb and cleaning it with some carb cleaner. I turned the pilot just till it was seated, and then turned it counter clock wise 2 turns. I noticed the pilot screw adjusts a small needle like pin. I also noticed the bottom of the carb has 2 caps, I just happened to unscrew the outer most cap and not the other one. The reason I mention this is when I installed the carb back on the bike, I tried adjusting the pilot screw, while the bike was running and hot and I noticed absolutely no change at all. I turned it clock wise till it stopped and the bike did nothing, then turned it counter clock wise till it stopped and the bike did nothing. Did I uncap the wrong screw? And have been adjusting the wrong screw altogether?

Should I uncap the other one and try again? If so, where should the other screw be set at? 1 turn, 2 turns or seated completely? Thanks again for the help.

[blaine]

If you are getting no change when adjusting,you are either on the wrong screw or your idle circuit is completely plugged. when you remove the idle mixture screw there should be a spring & o-ring on the screw.make sure you don't loose them.The mixture jet is pointed on the end.It should be set at 2 turns out to start than adjusted with the bike running.Jet should look like 3rd one in pic.


:) :cool:
http://s15.postimage.org/odck4hquf/images.jpg (http://postimage.org/image/odck4hquf/)

[Fausto]

If you are getting no change when adjusting,you are either on the wrong screw or your idle circuit is completely plugged. when you remove the idle mixture screw there should be a spring & o-ring on the screw.make sure you don't loose them.The mixture jet is pointed on the end.It should be set at 2 turns out to start than adjusted with the bike running.Jet should look like 3rd one in pic.


:) :cool:
http://s15.postimage.org/odck4hquf/images.jpg (http://postimage.org/image/odck4hquf/)

Hi Blaine. Thank you for your help it is very much appreciated. But I am not a bit more confused than what we started with. What is the mixture jet? Is that the same as the Pilot Screw? Also in the picture you mention the "3rd one in the pic" is the the 3rd one from the left?
Thanks man.

I looked at this post from viewtopic.php?f=8&t=617 (http://www.gz250bike.com/forum/viewtopic.php?f=8&t=617) and it has a picture of the bottom of a carb and it looks like I did uncapped the right screw. I dont know what to do next.

[blaine]

Yes pilot jet & idle mixture jet two different names for same part.Yes 3rd from the left.Start with 2 1/2 turns out & adjust slowly to were idle is smoothest.
:) :cool:

[Fausto]

Hey guys,
I gave up. I could only adjust properly and guess what I was doing was correct. I took it to a shop and coughed up $225 for it to be serviced. I dont regret it though, the shop owner did a good and went far and above took the bike to emissions himself. He said my chock was stuck and bent so it would close or open properly, my boots were not aligning properly and my jets were not cleaned completly. I drove it home and wow did it feel completly different. I'll report back after a put a few miles and see how it is doing.
In the mean time, how the hell do I fight the temptation to adjust the idle mixture screw just to see where it is set at? lol And that shitty feeling when a different motorcycle flies by me sounding like a chopper, how do I fight the need to drill holes in my muffler and mod it just so that my bike dont sound like a quad?

Thanks to all that helped, It is very much appreciated.

[mrlmd1]

In the mean time, how the hell do I fight the temptation.................... And that shitty feeling when a different motorcycle flies by me sounding like a chopper, how do I fight the need to drill holes in my muffler and mod it just so that my bike dont sound like a quad?

Thanks to all that helped, It is very much appreciated.

Don't do that. Not only will you hate the sound but you may have to rejet or play with the carb again if it doesn't run right, and you will get all messed up or pay again for someone to try and fix it. This bike is what it is, it will never sound a whole lot different, never like a Harley or a Gixxer (big sport bike).

[Water Warrior 2]

In the mean time, how the hell do I fight the temptation.................... And that shitty feeling when a different motorcycle flies by me sounding like a chopper, how do I fight the need to drill holes in my muffler and mod it just so that my bike dont sound like a quad?

Thanks to all that helped, It is very much appreciated.

Don't do that. Not only will you hate the sound but you may have to rejet or play with the carb again if it doesn't run right, and you will get all messed up or pay again for someone to try and fix it. This bike is what it is, it will never sound a whole lot different, never like a Harley or a Gixxer (big sport bike).
Absolutely agree. Leave it alone. You can't fix something that isn't broken. The GZ is what it is. Learn to appreciate the bike for what it is and do not try to make a chopper or sport bike out of it. You will never succeed.
The GZ is a simple reliable staple in the motorcycle world that will serve you well with a little TLC and regular maintenance. Ride the bike within it's limitations and don't ask for more. You will be surprised and happy to find a GZ can take you almost anywhere a larger bike will but a lot cheaper and a bit slower so you can enjoy the sites and smell the flowers more readily.