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.

Well I put in a new petcock and that seemed to cure my idle issues. It purrs like a kitten again. I have since got a new/used rectifier from a guy "guaranteeing" it to work. After I put it on, I have the same results as before. It will run up to half throttle and then it seems as if it hits a throttle limiter. It will rev up and then back down, just cycles through it if you hold the throttle wide open. There will be a bit of a backfire in there as well. Do you guys have any ideas of what to try next? Carb is rebuilt, air cleaner is new/clean, rectifier should be good, new petcock without vacuum and capped off on the carb. Whats next?!

I had a petcock off of an old WR that I had and slapped that in there...it helped but didnt cure it. It would idle for the most part but there would be random times that it would miss, almost like someone gasping for air, and then pick back up and run fine. At the higher RPMs it was still spitting and sputtering. So yes Oxidized I think that the rectifier may have an issue. I placed an order for a "guaranteed to work" used model off of eBay. Guess we will see if that is my issue. If not, any other ideas?

Definitely not a 2 stroker smoker.

I cant be certain on the fuel supply. As I understand it those petcocks are junk on Suzuki's in turn, that is why they put on a good ol Yamaha petcock. So I am replacing the petcock tonight to get rid of the "prime" and blocking off the vacuum port on the carb. Hopefully its a fix. If not, I will look into valve lash. Thanks.

I have no spare carbs for this wheeler sitting around...or else I would try it. That is why I rebuilt the carb for $40 though! I cant afford a new carb.

Nope, no mods made to the wheeler. Its bone stock. The jets are all stock and correct as it ran perfect the week prior to my issue coming a long. The needle only has one position, so its correct. I have since rebuilt the carb with a Shindy carb rebuild kit....everything was replaced correctly. The entire carb is clean as I left it in some solvent for a couple days. The reason I think its fuel is because its not a constant like it might be with electrical. The rectifier is in good shape, its got a new plug, the battery is newer, the grounds are solid. As I understand it, from other forums like you suggested, the problem could be getting fuel through the petcock because of the diaphragm or gasket in there gets fouled up. Also as I understand it they work off of vacuum in turn causing funny problems. So the solution I am going to try is putting on a Raptor 660 petcock (perfect fit) and blocking off the vacuum port on the carb. Apparently it fixes everyone's ailments. Thanks for your input welder.

I bought a little 250 for my wife and we took it out right after that and it ran great. Came back to the shop, parked it for about a week or two with a few starts in between, and then went out over the weekend and it started cutting out and backfiring into the carb. It seems like the choke was sticking cause it was "loading up" and you'd have to give it a bunch of gas to get it running again. It won't idle while in gear, or in neutral for that matter. It runs for a few seconds and then will backfire and die. There was a bit of smoke that would come out the top of the carb as well. When I'd have it running and in any gear, I'd take it up to about 3-4000 rpms and you could hear it cutting out a bit. No pattern to it, just random cutting out. However, when going through the gears at full throttle it ran fine. Since, I have rebuilt the carb with a Shindy rebuild kit. Everything went in fine and even put in a couple new diaphragms. I cleaned the carb bottom to top, it sat in solvent for a couple days. It should be like new now but the problem still persists. I need help, please!

No help? Anyone? Beuhler....Beuhler...Beuhler???

Hey all! I am new on here and searched around to see if I could find a solution to my issue. There were a few threads that beat around the bush but I didn't find one that nailed my problem. So here it is (hopefully not again)! I bought a little 250 for my wife and we took it out right after that and it ran great. Came back to the shop, parked it for about a week or two with a few starts in between, and then went out over the weekend and it started cutting out and backfiring into the carb. It seems like the choke was sticking cause it was "loading up" and you'd have to give it a bunch of gas to get it running again. It won't idle while in gear, or in neutral for that matter. It runs for a few seconds and then will backfire and die. There was a bit of smoke that would come out the top of the carb as well. When I'd have it running and in any gear, I'd take it up to about 3-4000 rpms and you could hear it cutting out a bit. No pattern to it, just random cutting out. However, when going through the gears at full throttle it ran fine. I have went through the carb and cleaned up everything as best as possible. There were some o-rings that could have been replaced but didn't have any. I put it back together without the new ones but they are on order. There was one thing of curious note...on the diaphragm on the top of the carb, there is/should be a brass cylinder on the outside of the diaphragm. It is now missing. Will that make the difference? I always thought it was for idle purposes. I know its supposed to be there cause I have saw them plenty on my R6 carbs. (nearly robbed one out of my spare set of carbs) Overall, I'd like some input on why this is happening and what I can do to fix it. Are there any rebuild kits out there worth a crap? Let me know...and sorry for being so long winded!