[deltaklr]

Okay. This is going to be a rather long explanation, but I want to be thorough and I am in desperate need for some help.

About 4 months back I was riding my bike and it just died on out of the blue. At the time it did not seem like it was a fuel is being as it just died when I laid on the throttle and there was no sputtering like a fuel issue would have caused. I got the bike home and checked the charging system and made sure the spark plug was good and had a good spark. They were both fine. I then moved over to the fuel system and checked to make sure the vacuum was opening the petcock like it was supposed to. Fuel was flowing to the carb with no issue, but he bike would not start. It would crank fine though. (upon further inspection I found I had quiet a bit of water in my gas)

I then removed the carb and cleaned it thoroughly, removed all of the fuel with water in it and installed it back on the bike and filled with fresh gas. The bike started right up once I had everything back in place. I was so excited at this point. I rode the bike home and put it up. At this point it was the dead of summer so I was not really riding (too hot in the Delta). I went out once or twice a week and cranked it up and let it run for 10 to 15 minutes. It showed absolutely no signs of the previous issue.

One cool afternoon about a month ago I decided to go for a ride. I hit some turn roads close to the house and rode pretty hard for about 20 minutes and the bike started to sputter and then died on me in the middle of nowhere. I tired cranking the bike back up and it would not start at all. Not even think about it. I removed the fuel line to make sure it was getting fuel and it was flowing just fine.

I took the carb back off and cleaned it once again thinking there may be some small trash in the carb that is getting in the jets. I did this twice with the same results. It would start right up and then run for a while, sputter then die and not start back up. The times I could ride before the failure were not consistent. I thought it might be the CDI box or coil getting hot and cutting out, but the way it sputters leads me to fuel issues.

I ordered a carb rebuild kit and a petcock conversion (from vacuum to standard). I installed both and put the bike back together last night. I did do the .22 mod while I was in the carb this time, but did not drill the slide. Aside from some air filter issues (damn K&N POS. I am returning and going with a foam UNI) everything went smooth. I turned the fuel on and waited a few seconds. I then tried to start the bike and once the bowl was full of fuel it started with no hesitation. I let the bike run for 20 minutes or so idling on the stand and revved it up a few times. The only thing I noticed was a slight backfire at around 6k rpms.

I called it a night and decided I would do some more tweaks this afternoon. I originally just installed one washer on the .22 mod and did some more reading were people put two. I took the top off and installed a second washer and drilled the slide this afternoon. Once I had it all back together I was going to get all of the screws adjusted. Once it was together I started the bike (once again with no issue) the idle was slightly high though. I adjusted the idle screw down one turn to get it around 1000 rpms. The bike appeared to be running great. I was letting it run while I got the side panels and seat back on the bike and I was going to ride it around the parking lot. While it was on the stand just idling it died a couple of times and would start back up.

By the time I got it all together and was going to ride it died and would not start at all. I turned it over for a while and every now and again it would hit and act like it was going to start then it would die immediately. A couple of times it would run as long as I held the starter and then die as soon as I let off. Towards the end of the regular running it did appear to be a little rich. While I was trying to start it with no luck it did backfire a few times as well. No running, just a back fire.

Does anyone have any suggestions of what to try next? The weather is beautiful and I am ready for a road trip! Could it be my valves sticking or needing adjusting? I have not checked them and honestly don't know if they were done by the previous owner.

04' klr with 8500 miles

Any suggestions will be greatly appreciated and let me know if I left any important diagnostic information out. I tried to cover the bases.

Thank You.

 

[willys]

First off....welcome to the site....it is a great place to hang your hat and stay a while....people here are super friendly without the normal internet stress thrown in for good measure.

I have an 04 also....I also had what you are discribing......it nearly drove me to drink! What I did was almost what you have done already except a few other things. I bypassed all safety switches. I cleaned up the ignition switch as best as I could, I just flowed it with a good cleaner such as WD40 and then once that was not washing any dark coloured fluid out flooded it with a good electrical dilectric type oil.....just to keep more lube than the WD in there. I then went after all electrical connections, cleaned them with a small tiny file and filled each connection with dilectric grease. Then I went after the coil wire to see what condition it was in, it wasn't the best as it would turn at each end and not tighten up on the screws in each terminal so I trimmed just a small amount off the wire and reinstalled so each end was firmly attached. Then I accidentally looked past the screen in the airbox(I have removed my screen for better flow) and found that I had a hole burned, melted in the bottom of my airbox. I repaired it. Now seriously concerned I had debris in my bore and damaging the cylinder walls.....but that wouldn't cause the issue, but a lean mixture could have contributed towards it. I also cleaned my carb so meticulously it was crazy. I also cleaned each of the started switch, and starter relay and ground for the starter.....I was grasping at staws with some of the things I did to solve this. What finally did it was I replaced my voltage reulator.....why this did it is besides me...it shouldn't have had anything to do with the symtoms from what people with more electrical knowledge than I have. But it did. It is an expensive item to buy unless you get another used one off fleabay. I chose to buy new from the dealer and paid hansomly for the thrill! $164 if I recall correctly!!! I have since bought another used one to carry as a spare, same as another coil and CDI box.....they are all bolted to my frame at locations where they will fit to be unbolted IF this ever happens again. But it hasn't.

Now after saying all of that....this past summer a group of us rode to Dawson City and all of us had exactly what you are discribing.....we all got bad gas at some point or other. We all changed all electrical items thinking what I have said above. We all cleaned our carbs as best we could on the side of the road. After cleaning the carbs the bikes would run for a while and then putter out and have the same symtoms again. I would strongly suggest cleaning your carb completely again using Pinesol and letting it soak overnight submerged in the Pinesol. Don't put the rubber items in the solution, but take everything else completely apart and soak them. Then take them out and wash with warm or hot water to get the Pinesol out of the carb etc, then I use spray carb cleaner to blow each air/fuel passage through and each jet etc to get any water that will still be in each location. Then I use compressed air to finally blow all fluids etc from each passage and jet. Then I visially check each to see if there is anything I can see blocking each jet etc. You can see when you spray carb cleaner through each air/fuel passage if it's clear or not at that time. Be very careful not to get the carb cleaner into your eyes when doing this....it can happen as you don't always know where it will come blasting out from. If you do all of this long winded reply and still have issues......start after the wiring harness for a short that could be rubbing against the frame or some other ground or bare wire creating the problem. This is the worst to try and find....imho. that is why I leave this to the end. Well before I buy expensive electrical parts that is.

I really hope this helps you fix your problem.......:13:

 

[deltaklr]

I tired to start the bike this afternoon and it started up with no hesitation. I cut it off and came back about an hour later. I started it back up and it ran for about 15 seconds and then died. I tried starting it up again and it would run as long as I would hold the starter button down and would die as soon as I would let off. I took the switch apart and all of the solder points look good and all of the wires look good. I wonder if the switch is bad or if there is a ground issue in the starter system.

I also forgot to mention last night while the bike was running for a while with no issues the gas tank seemed to pressurize. I was standing there when the bike died and I could hear a hissing sound. I opened the gas cap and there was a gush of air. I then closed the cap back and let it sit for a couple of minutes and it did the same thing again. I felt the tank and it was slightly warm, I checked the diaphragms in the cap assembly not to long ago and it was all clean and functioning properly. Any idea what the cause of this could be? The vacuum petcock has been converted. The only fuel line is the line out to the carb and the vent line under the seat.

 

[willys]

What happens if you tried running the bike with the gas cap open? Does it still cut out and die? If not I would bet there is a vacuum being built up in the tank restricting the flow or amount of gas getting to the carb.
The tank will purculate so to speak in the heat of a hot day as the gas fumes expand, they will be released through the cap vents making that kettle sound.:13:

 

[deltaklr]

It does the same thing with the cap open. I am almost certain it is electrical. I have a friend that works on 4wheelers fairly regular. He seems to think it may the the CDI box getting hot and causing the issue; however, the new issue appears to be instant. Not heat related.

 

[willys]

If it is at all possible see if you can find someone willing to risk their CDI or voltage regulator or coil to see if that fixes the issue......or buy them used from fleabay with the end thought being that you will always have spares as I do on long adventures far from home.
Looking for a short in your wiring harness will drive you to drink...! I untaped my entire harness part by part to try and find a short......if you take the entire harness a part in one shot it will be very difficult to get it taped back up correctly to fit where it is supposed to fit.....I found this out the hard way even doing short sections at a time. I must have gone through numerous rolls of electrical tape redoing sections when I couldn't get the harness to easily fit where I needed it to fit. Beware!
Like I said before...it was my voltage retifier that finally fixed mine.....why I don't know exactly. I always thought it would get warm and a cold solder joint would seperate and not allow it to work. It was getting hotter than I liked but....it supposed not to effect the general running or not running of the bike from what some with more electrical knowledge keep trying to tell me. All I know is....once I switched it out the problem was gone. I also moved it up to the front where it can get a good flow of fresh air to keep it cool. Never an issue since....Hope this helps.....:13: