Rocktech
XS400 Member
Hi all, I just bought a a 1980 xs400 special. I love everything about it. Except for the fact that it died the day after I drove it home. It kept acting like it had run out of fuel. (Yes there was fuel in it and yes I switched it to res.)
All that to say, I’m pretty handy, though this is my first bike. So after research and not being able to contact any bike mechanic nearby. I started with what I knew, an oil change. Then I ventured into cleaning the air filter and then the carbs. Cleaned the carbs, and replaced the boots and vacuum hose to the petcock. Here is what I have noticed. Maybe they are separate and maybe not:
1. It idled fine for a few min off choke, I was letting it warm up and then out of nowhere it rev’ed itself up to around 5k rpm and got stuck there. After I shut it off, I started again, idled fine. But whenever I blip the throttle it revs up again and sticks around 5k. Throttle cable is not getting stuck, it is snapping back. What causes this?
2. After startup, I noticed cold clean oil dripping from under the gear box.where the the wires come down to the back left of the oil screen.
3. I noticed really mucky oil and burning oil smell coming out of the (if you are sitting on the motorcycle) left header. Where it connects to the exhaust. And there is mucky all around where the spark plug goes in on that left side.
any next steps in any of that would be helpful as I want to learn to work on this motorcycle myself. And the only mechanic that finally replied is booked till January. The goal is just to get the bike running reliably to get to work and back before adding mods.
Thank you,
Rock
All that to say, I’m pretty handy, though this is my first bike. So after research and not being able to contact any bike mechanic nearby. I started with what I knew, an oil change. Then I ventured into cleaning the air filter and then the carbs. Cleaned the carbs, and replaced the boots and vacuum hose to the petcock. Here is what I have noticed. Maybe they are separate and maybe not:
1. It idled fine for a few min off choke, I was letting it warm up and then out of nowhere it rev’ed itself up to around 5k rpm and got stuck there. After I shut it off, I started again, idled fine. But whenever I blip the throttle it revs up again and sticks around 5k. Throttle cable is not getting stuck, it is snapping back. What causes this?
2. After startup, I noticed cold clean oil dripping from under the gear box.where the the wires come down to the back left of the oil screen.
3. I noticed really mucky oil and burning oil smell coming out of the (if you are sitting on the motorcycle) left header. Where it connects to the exhaust. And there is mucky all around where the spark plug goes in on that left side.
any next steps in any of that would be helpful as I want to learn to work on this motorcycle myself. And the only mechanic that finally replied is booked till January. The goal is just to get the bike running reliably to get to work and back before adding mods.
Thank you,
Rock
