83 500 virago won't start
Hi all, I'm new here. I hope I have problem some of you can help me with. I have a 83 Yamaha Virago 500 that I just picked up and it won't run. The starter clutch was bad and it had been sitting. The guy I got it from said it ran until the starter clutch went out, but I have no way to know for sure. I replaced the starter clutch. When I put the flywheel back on I checked to make sure the cotter key was in place and everything lined up. I then pulled the carbs to clean and they really did not look too bad, but are now well cleaned. The bike still would not run. It really does not sound like it is trying to start. I replaced the spark plugs and set the gap to spec. The spark does not look real strong, but I would think it would be enough to run. I removed the coils and checked them with a coil tester, they were fine. I also used a spark checker inline with the plug installed and when turning the motor over I do get a spark that jumps the tester gap of about 3/8th inch. I did a compression test, and even cold the compression is good. When trying to start it does absolutely nothing except an occasional backfire. I tried reversing the coils to make sure they were not wrong and no luck. I pulled the cam gear covers off each side and turned the crank with a wrench to see if the cam timing was off. With the flywheel on the 1st cylinder TDC mark the dot on the cam gear is straight up (in relation to the cylinder) and when I turn the flywheel to the other cylinder TDC mark, the cam gear dot is straight up on the front cylinder. There is no mark for the dot to line up with, but I assume that 12:00 is correct. It won't even try to start with some starting fluid; it just turns over until it backfires. Any ideas of where to look would be appreciated. I also have a few more questions and hope someone might have some insight. I was wondering why this bike even needs a fuel pump with the tank located above the carbs. Also there is the fuel line that goes out of the petcock to the pump. Then from the pump to the carbs and then from the carbs back to the petcock. I am not talking about the vacuum line for the petcock. Is the extra line a return bypass? Can you run this bike without the fuel tank with an aux tank on a stand? Maybe run a fuel line from the carbs that would go back to the petcock to a fuel can to catch any extra fuel. I have emptied and replaced with fresh fuel in the tank and I know I am getting fuel to the carbs because I can open the drain screw and fuel runs out. I also took the fuel pump apart and cleaned/checked it. There are no rips or cuts in the membrane material. Also, it will not start on starter fluid either. Doesn't even act like it is trying to start until it backfires or after fires when you crank it for 5 seconds or so continually. It also spins over well, doesn't seem to drag or anything.