ba9801
Well-Known Member
OK here is the situation
I built this 87 warrior from a bare frame. It was a running bike before we took it apart but it ran poorly as the cylinder was well worn and the carb was a mess. Anyway we disassembled the entire bike, sandblasted it and painted the frame. I had the cylinder bored and a new Wiesco piston put in, I rebuilt the Mukuni VM 36 carb. The wiring looked to be in good shape but had new battery cables made up for it anyway. I put a new MSD ignition coil on it and a good used Key switch and headlight switch as the guy before me was racing it and had no lights and a tether kill. It has a new battery as well. OK so here is the problem.... The complete bike is assembled and we are getting no spark so I tried the original coil that was on the bike when we got it along with one on a running 92 warrior. Still no spark. Ok so we started testing some things and we were not getting any signal out of the CDI to the coil so I bought a brand new Yamaha CDI. We seam to have some signal coming out of the CDI now but not enough to fire the coil. I have tested the Pickup coil and the resistance is 192 ohms, it calls for 230-300 or so, Is this enough to cause a problem with the signal to the CDI? I am not worried about the carb or engine as being a problem at this point. I have tried to run the engine on carb cleaner and no effect, also I have checked the timing chain 3 times to make sure we are on TDC. We do have compression and everything mechanically seams to be working well. I then though I may have a problem with the connector from the magneto to the harness so I cut off the connector and directly connected the wires, this made no difference either. We have checked both the ignition switch and kill switch for continuity and they are good and working when you change the positions on the switch. Also we are able to manually fire the ignition coil by powering it up so the coil looks to be good as well. We also tried 3 different spark plug wires and 2 spark plugs. I have also run additional grounds to make sure it is not a problem with too much paint on the frame. Also when I painted the engine the spark plug was in and taped up so I know the spark plug is grounded to the engine as the head was sandblasted when it was all apart.
Any help sorting this problem would be very appreciated as it is my wife's bike and she would really like to go riding.
Thanks
I built this 87 warrior from a bare frame. It was a running bike before we took it apart but it ran poorly as the cylinder was well worn and the carb was a mess. Anyway we disassembled the entire bike, sandblasted it and painted the frame. I had the cylinder bored and a new Wiesco piston put in, I rebuilt the Mukuni VM 36 carb. The wiring looked to be in good shape but had new battery cables made up for it anyway. I put a new MSD ignition coil on it and a good used Key switch and headlight switch as the guy before me was racing it and had no lights and a tether kill. It has a new battery as well. OK so here is the problem.... The complete bike is assembled and we are getting no spark so I tried the original coil that was on the bike when we got it along with one on a running 92 warrior. Still no spark. Ok so we started testing some things and we were not getting any signal out of the CDI to the coil so I bought a brand new Yamaha CDI. We seam to have some signal coming out of the CDI now but not enough to fire the coil. I have tested the Pickup coil and the resistance is 192 ohms, it calls for 230-300 or so, Is this enough to cause a problem with the signal to the CDI? I am not worried about the carb or engine as being a problem at this point. I have tried to run the engine on carb cleaner and no effect, also I have checked the timing chain 3 times to make sure we are on TDC. We do have compression and everything mechanically seams to be working well. I then though I may have a problem with the connector from the magneto to the harness so I cut off the connector and directly connected the wires, this made no difference either. We have checked both the ignition switch and kill switch for continuity and they are good and working when you change the positions on the switch. Also we are able to manually fire the ignition coil by powering it up so the coil looks to be good as well. We also tried 3 different spark plug wires and 2 spark plugs. I have also run additional grounds to make sure it is not a problem with too much paint on the frame. Also when I painted the engine the spark plug was in and taped up so I know the spark plug is grounded to the engine as the head was sandblasted when it was all apart.
Any help sorting this problem would be very appreciated as it is my wife's bike and she would really like to go riding.
Thanks