First things first I have little to no mechanical inclination.
Got my hands on a 1979 Yamaha XS750. Super cool bike, and it ran so good and got me home when I bought it. Well, almost. Around 50 minutes into the ride one of the air filters fell off and it died out, couldn’t find the filter. Shop down the road didn't have the right size but I needed something so I cut the foam off and zip tied it around the air intake. Bike started but ran rough. Got me another 20 minutes or so of riding until it died again. Managed to start it but it needed choke now. 15 minutes later the bike bogged out and wouldn’t start again. I guess it was a sign from god because I ended up directly across the street from a 24/7 roadside service garage. Had to leave it there for the night. Next day, I go out to get it and the guys there offered to take a look at it. Spark plugs were bone dry and blackened. They did something to the idle screws and got it to run, made it home and idled well until it eventually puttered out. Hasn't started since. In the past few days Ive done a few things to see what it could be.
What Ive done: Taken apart the carbs, there were some deposits in the float chambers and the floats weren't too good. Cleaned them, seems fine. One of the pistons wouldn’t go all the way up and were sticking, so I took them out, cleaned them and fixed the diaphragm. I also replaced the fuel line and fuel filters. The battery is pretty dead, and the bike doesn’t spark. One fuel filter is full and the other is empty. Petcock isn’t the issue and I unscrewed the bottom of each float bowl and theres fuel. No fuel to the plugs.
What could’ve caused this from the time the filter fell off to when I made it home? The bike ran good when I bought it but maybe should’ve had more power, I have an XJ550 in relatively rough shape and seems more powerful than this. Do I need new floats or float needles? Do I need a new battery or spark plugs? Any advice would be very appreciated.
Got my hands on a 1979 Yamaha XS750. Super cool bike, and it ran so good and got me home when I bought it. Well, almost. Around 50 minutes into the ride one of the air filters fell off and it died out, couldn’t find the filter. Shop down the road didn't have the right size but I needed something so I cut the foam off and zip tied it around the air intake. Bike started but ran rough. Got me another 20 minutes or so of riding until it died again. Managed to start it but it needed choke now. 15 minutes later the bike bogged out and wouldn’t start again. I guess it was a sign from god because I ended up directly across the street from a 24/7 roadside service garage. Had to leave it there for the night. Next day, I go out to get it and the guys there offered to take a look at it. Spark plugs were bone dry and blackened. They did something to the idle screws and got it to run, made it home and idled well until it eventually puttered out. Hasn't started since. In the past few days Ive done a few things to see what it could be.
What Ive done: Taken apart the carbs, there were some deposits in the float chambers and the floats weren't too good. Cleaned them, seems fine. One of the pistons wouldn’t go all the way up and were sticking, so I took them out, cleaned them and fixed the diaphragm. I also replaced the fuel line and fuel filters. The battery is pretty dead, and the bike doesn’t spark. One fuel filter is full and the other is empty. Petcock isn’t the issue and I unscrewed the bottom of each float bowl and theres fuel. No fuel to the plugs.
What could’ve caused this from the time the filter fell off to when I made it home? The bike ran good when I bought it but maybe should’ve had more power, I have an XJ550 in relatively rough shape and seems more powerful than this. Do I need new floats or float needles? Do I need a new battery or spark plugs? Any advice would be very appreciated.
