dgoodsy
XS400 Enthusiast
Hello everyone,
I'm new here (obviously), and new to old bikes as well, although not new to bikes entirely. I grew up with a dirtbike, and had a newer street bike for a few years as well. This week I purchased an xs400 from a friend and have been on this site many times already looking for guidance, looks like a lot of help and inspiration here! I figured I would start this thread to document modifications, fixes and ask questions.
I'm not sure what direction I'm going to with this bike yet, I like the brat look and the cafe racer look but I want a comfortable efficient bike to bomb around the city on. Whatever i end up doing i want to compromise as little comfort as i can. So for now I aim to take care of missed/unknown maintenance, have it running reliably and go from there.
My first question: what year is my bike? It was sold to me as an '83, however it is a SOHC bike I believe, and the VIN starts with 4T5. Most links I found don't list those first 3 digits of the VIN but I found one that called the bike an '81 xs400h, which I have assumed correct. Can anyone confirm or deny this?
I have done an oil/filter change and made some cable adjustments so far, nothing too serious yet. It runs very well, even with the fuel that sat in it for the last 18 months. It could use some tuning though as it has a few issues. It seems to hesitate or misfire at low throttle angles around 3500-4000rpms, but as soon as I give it slightly more throttle it clears right up. It also idles way quicker warm than cold. If I set cold idle (warm enough that it idles nice with the choke off, but not fully warmed up yet) to 800-1000rpms (haven't looked up specs on what idle should be, just set it to what the engine seems to like so far) it won't come down below 2000, maybe 2500rpms after it is fully warmed. Maybe I just need to set the idle lower and leave the choke on longer, I haven't played around too much yet.
I have parts ordered to refresh the fuse panel, I should be able to do that next week. Since the fuse holders/clips were broken or weak someone had used tiny wires wrapped around the clips to hold the fuses in better. It should be no surprise that contact was intermittent at best. Also the main fuse had been removed and the 2 wires twistd together and taped up. I have used some female spade connectors and regular blade fuses as a temporary fix.
I also adjusted the clutch cable to fix the issue with the kick starter not engaging. I assume there is a Yamaha too to adjust the screw and locking nut inside the clutch side cover, but I don't have it. I ended up having to use an electric impact wrench to loosen and tighten the nut which seemed to work good although not what Yamaha would recommend.
The bike also may have a charging issue that I hope to test next week as well.
That's all for now
edit:
here are a few pictures of the bike at work today. Not the best pics but you get the idea.
I'm new here (obviously), and new to old bikes as well, although not new to bikes entirely. I grew up with a dirtbike, and had a newer street bike for a few years as well. This week I purchased an xs400 from a friend and have been on this site many times already looking for guidance, looks like a lot of help and inspiration here! I figured I would start this thread to document modifications, fixes and ask questions.
I'm not sure what direction I'm going to with this bike yet, I like the brat look and the cafe racer look but I want a comfortable efficient bike to bomb around the city on. Whatever i end up doing i want to compromise as little comfort as i can. So for now I aim to take care of missed/unknown maintenance, have it running reliably and go from there.
My first question: what year is my bike? It was sold to me as an '83, however it is a SOHC bike I believe, and the VIN starts with 4T5. Most links I found don't list those first 3 digits of the VIN but I found one that called the bike an '81 xs400h, which I have assumed correct. Can anyone confirm or deny this?
I have done an oil/filter change and made some cable adjustments so far, nothing too serious yet. It runs very well, even with the fuel that sat in it for the last 18 months. It could use some tuning though as it has a few issues. It seems to hesitate or misfire at low throttle angles around 3500-4000rpms, but as soon as I give it slightly more throttle it clears right up. It also idles way quicker warm than cold. If I set cold idle (warm enough that it idles nice with the choke off, but not fully warmed up yet) to 800-1000rpms (haven't looked up specs on what idle should be, just set it to what the engine seems to like so far) it won't come down below 2000, maybe 2500rpms after it is fully warmed. Maybe I just need to set the idle lower and leave the choke on longer, I haven't played around too much yet.
I have parts ordered to refresh the fuse panel, I should be able to do that next week. Since the fuse holders/clips were broken or weak someone had used tiny wires wrapped around the clips to hold the fuses in better. It should be no surprise that contact was intermittent at best. Also the main fuse had been removed and the 2 wires twistd together and taped up. I have used some female spade connectors and regular blade fuses as a temporary fix.
I also adjusted the clutch cable to fix the issue with the kick starter not engaging. I assume there is a Yamaha too to adjust the screw and locking nut inside the clutch side cover, but I don't have it. I ended up having to use an electric impact wrench to loosen and tighten the nut which seemed to work good although not what Yamaha would recommend.
The bike also may have a charging issue that I hope to test next week as well.
That's all for now
edit:
here are a few pictures of the bike at work today. Not the best pics but you get the idea.
Last edited: