dag1911

Can anyone else give me their two cents?? Id appreciate any input you have.

It runs like the video...until it runs out of gas.

Yeah there is. New Yamaha style petcock and got rid of the vacuum port on the petcock and blocked off the port on the carburetor. Also on the cap I have a good vent hose coming off of it. I took the line off the carb and let the fuel run through the petcock, filter, and line and it ran freely. No blockages.

The only way the fuel is getting pumped is by mother nature, gravity. There isnt a fuel pump. But I agree, I think its a fuel issue...perhaps jetting. Not sure cause it ran fine at this elevation prior and it has stock jets in it. So one would think that is a fine base point to start from with minor adjustments thereafter.

Ah yes, I could see that for sure. Nah it starts with just a tiny tap of the starter button. Its always been that way. Plus, this one doesnt have a pull starter. In the 2nd video I just posted you can hear it idling like a champ right off the bat. When I give it gas is when I encounter the problems. Check it out and let me know what you think.

Here is another video after I turned the air screw IN a quarter of a turn. [ame=http://www.youtube.com/watch?v=tXwF10QGcL4]Throttle test 2 - YouTube[/ame]

Haha no I am not...Id have a shot starter as well if I were!

Hey guys! I am in need of some serious help with my little quad. Take a listen to the video and see if you can decipher why it is running like it is. I have yet to figure it out. I have cleaned and rebuilt the carb with OEM parts and jets. Put in a new petcock, fuel filter, and fuel line. Replaced the computer. Put on a new coil, wire, and cap. Replaced the spark plug. Checked the compression and valves. Everything was in spec with the manual. I am at a serious loss. Please let me know your thoughts. [ame=http://www.youtube.com/watch?v=3DsTZ23nK6o]2004 Suzuki LT-Z250 - YouTube[/ame]

That was my first thought as well. Its in a bad place...right in front of the head so the heat surely builds up quite a bit there. (I ordered a coil sunday night...it gets here today). I will let you know if that cures it!

Have you guys ever had an issue where your wheeler runs great the first 10-15 minutes of the ride up and down hills, slow and fast speeds, and then it just peters out? It starts cutting out real bad and not making the RPM's like its supposed to? Well if so, help a brotha out cause that is what mine is doing. What would cause it to just quit after it is thoroughly warmed up like that?

So I thought I would give an update as to where I am at on this issue I am STILL having. I have tested the coil and it came out in the correct ranges. So that should eliminate a bad coil/spark plug cap. Over the weekend I bought a new CDI box since I didn't have a good way to test it and don't really know anyone where I live since I just moved there. I put the CDI box in, same issue as always. Starts and idles just fine with the choke on. Take the choke off after it is warmed up, it idles fine for a bit then just dies like its gasping for air. After that I start it back up, put the choke on, give it throttle to halfway, it stumbles cutting in and out without dying. It does that clear up to full throttle. RPM's up to say 7000 and back down to 2000. Just a vicious cycle. So obviously the CDI wasn't the issue. Also I did a compression check, I am at 190 psi and the lower service limit is 171psi and standard is 199psi. So my top end is fine. I checked the valves and they were in the correct tolerances on both intake and exhaust. I truly am at a loss right now. Can you guys give me any other ideas to try next?

Ok that is a good plan as well. I can check the compression and do a leak down test on it. The more I think about the scenarios and troubleshoot it...it seems likely that the coil is bad. I printed out the sheets from the manual I downloaded to test it. So that is on docket for tonight as well. Hopefully that will clarify things for me. Thanks for the input.

I have checked the grounds, which there arent many, and they looked good to me. However, I could be missing one some where? Do you have an overview of where all they might be so I can see which ones I have hit? All other connections seemed to be good but didnt go over them with a fine tooth comb. Perhaps the next step IS to look into a service manual. I didnt want to have to tear this hummer down already...

What kind of seals are "inside" the carb? I have replaced all the o-rings, the float bowl gasket, new jet needle diaphragm. It starts with just a tiny tap of the starter, it idles like a champ, just starts to cut out at about half to full throttle. Is that coil related? Just not getting enough spark? The gas is fresh and clean. How do I go about adjusting the valves? Are there any repair manuals that I can download off this site? Thanks for your help and ideas...its appreciated.