I am exerpriencing a very frustrating problem. My son bought a 1988 Yamaha DT200 last month. The bike seemed to work fine at first rides well and has good acceleration. It is a two stroke oil injected with YPVS.
When the bike starts it starts on the first kick and runs well. However at any random moment ( usually when you leave it for a while) when you try to start the bike it sputters, there is no or very little throttle response at all and then it quits after a backfire. Leave the bike for 2 or three hours come back to it do nothing different and it starts fine. Furthermore when riding for more that 40 mins or so it will start to run like it does as mentioned above ( sputters and then quits).
Here is what we have done so far. Carburetor has been rebuilt ( it was leaking fuel badly at times), new needle valve, new float, gaskets. The wiring and electrical has been checked. The horn doesn't work but that was troubleshooted to a bad pushbutton switch. The ignition system has been checked. Good fat blue spark every time. The timing, source and secondary coils all are within specs. New fuel line, new oil lines, fuel is new and flows well into the carb, petcock works fine, tank is in good shape and fuel is clean. I checked the battery and it is good. Charging system seems to work and the lights, signals etc all work fine. The ignition switch seems to work fine. When you turn the ignition switch on you can seem the oil level light disappear after a few seconds which is normal and the YPVS turns on it runs for a while until you start the bike. The specified compression for this bike is 116 PSI and this bike measure 110 PSI so its pretty close.
Several times I have pulled the plug after attempting to start the bike and the plug is wet with some carbon oil so it must be getting something into the piston chamber. Cleaning the or putting a new plug in doesn't help.
You can tinker with this thing then it mysteriously starts and runs fine for a while but like a demon always come back to haunt us.
Any have any experience with this bike? Is it the YEIS?? The only thing I haven't checked. :(
When the bike starts it starts on the first kick and runs well. However at any random moment ( usually when you leave it for a while) when you try to start the bike it sputters, there is no or very little throttle response at all and then it quits after a backfire. Leave the bike for 2 or three hours come back to it do nothing different and it starts fine. Furthermore when riding for more that 40 mins or so it will start to run like it does as mentioned above ( sputters and then quits).
Here is what we have done so far. Carburetor has been rebuilt ( it was leaking fuel badly at times), new needle valve, new float, gaskets. The wiring and electrical has been checked. The horn doesn't work but that was troubleshooted to a bad pushbutton switch. The ignition system has been checked. Good fat blue spark every time. The timing, source and secondary coils all are within specs. New fuel line, new oil lines, fuel is new and flows well into the carb, petcock works fine, tank is in good shape and fuel is clean. I checked the battery and it is good. Charging system seems to work and the lights, signals etc all work fine. The ignition switch seems to work fine. When you turn the ignition switch on you can seem the oil level light disappear after a few seconds which is normal and the YPVS turns on it runs for a while until you start the bike. The specified compression for this bike is 116 PSI and this bike measure 110 PSI so its pretty close.
Several times I have pulled the plug after attempting to start the bike and the plug is wet with some carbon oil so it must be getting something into the piston chamber. Cleaning the or putting a new plug in doesn't help.
You can tinker with this thing then it mysteriously starts and runs fine for a while but like a demon always come back to haunt us.
Any have any experience with this bike? Is it the YEIS?? The only thing I haven't checked. :(
