1. Sesty

    Top Carb Screws Stripped

    Just got my first bike, it's an 78 xs400E only has 7,500 miles At running temp the carbs dump fuel... A whole lot of fuel. Plan was to take carbs apart give them a good cleaning plus new gaskets. I got the carbs off and started at the bowls. Quick spray of WD40 on the screws and the bowls...
  2. M

    New XS400 owner full of dreams! (and questions)

    Hi everyone! I've had my XS400 for a week now, and I have to say I'm starting to like it! :P It hasn't been used much in the last 10 years, so the air filters had to come off right away since they had mildew in them. My idea is to slowly make it into a tracker-looking daily rider. I've...
  3. R

    Seca 400 Won't Start

    1982 Seca 400 I had it running a couple of days ago, but now I can't get it to start no matter what I try. The fuel line is clear, battery is new and charged. When I try to start it the first crank it turns over then promptly dies. This is with choke full. After that it cranks and cranks, no...
  4. R

    carb vinegar boil ?

    I'm gonna boil my carbs in vinegar but I'm wondering if I need to take any or all of the rubber pieces off first? And also is it alright to boil the floats as well? And is vinegar the best thing to use or is lemon juice better? Thanx.
  5. O

    Really need help finding parts...

    Ok so I was sitting back with my fiances brother showing him how to port n polish, did some light work to the head and then moved onto the carbs. So we were sittin there cleaning up the casting marks on the filter side and then polishing it smooth, with the carbs apart and cleaned up I left my...
  6. S

    new battery and bike won't start..need help

    Hey all, So I bought an 81 xs400 at the end of March. I haven't been able to ride it because I broke my wrist, but the day I bought it I rode it a bit around town and the bike ran perfectly. I broke my wrist the next day. I went out and tried to start the bike a week ago and it didn't start. I...
  7. thielb

    Two questions/mysteries

    1. This small metal piece was just bouncing around in the bottom of my airbox. What is it and where did it come from? 2. What are these lines and why are they cut and plugged?
  8. markjs

    Is there a need to adjust the cam chain tension?

    In my 1982 XS400J or my 1983 XS400K Maxim (DOHC) bikes? I remember having to do it with all my old Hondas but I've also heard some do not require adjusting. So on the DOHC is it something I need to do, and if so how? I looked in the manual and didn't see anything.
  9. markjs

    Grrr batteries and other general morning evil bike syndrome!

    OK, I'll try and keep this short but Frankenbike decided to hate me this morning and I think the answer is likely complicated. Anyway, the battery I was using went back to the guy who gave it to me (he changed his mind and made a gift into a loan when he needed it), so I got two batteries from...
  10. DrHans

    problems with carbs, xs400 1978

    Hello during the build I have found a problems I suspect it is carburators: The bike only starts with Choke On and runs very unstable, when opening the throttle bike turns Off. what may be a problem ? jets ? (if jets, what are sizes and names for replacement jets) carbs are: Mikuni...
  11. markjs

    Now that she's ready for the road, brakes need attention.

    First I want to take the time to thank everyone who helped me. My attitude has sucked for a few days because I really need this bike to work and I was so frustrated, but then all is well that ends well, so thank you fellow board members, you guys are top notch!:thumbsup: So, my front caliper...
  12. maxholland1

    Sprocket Side Cover (Allen Bolts)

    Anyone know where to get the sizes for the Allen Bolts? I got a cover without any. Would it be in the Manual? Any other places?
  13. K

    81 xs400 died on throttle

    I have a 1981 xs400 that ran perfect for about 6 months and one day started dying on throttle. It idles ok but not as well as it should. I rebuilt the carbs, checked all the wiring, petcock, vacuum hoses... everything. Still died on throttle. Can anyone help me?
  14. danisawesome

    Rust, carbs, starting, suspension, and petcock questions!

    (How's that for a descriptive title?) Alright, I have some questions for you XS masters. Sorry for the wall of text, but any help is appreciated! Also, I don't have my bike at my apartment, or even in the same state as me, so some of these questions I could solve myself but I just don't have...
  15. maxholland1

    Should I buy this bike?

    Hey everyone, I am looking at getting this XS400 for $250. The engine was seized, but it has been seized by a bike mechanic. I am willing to put around $400-$600 into making it run smoothly. I have attached pictures. Any advice, any perspective? I have a friend who is willing to walk me...
  16. 2


    I have a non heated garage that I am building my bike in should I do anything to the engine incase it freezes in my garage this winter
  17. sly409

    carbs and jet sizes

    So after successfully removing the broken mixture screw tip I'm ready to start rebuilding my carbs and upgrading the jets. Ive found that my current jet sizes are: 132.5 main jet 42.5 pilot jet I dont think the main jet is stock size as the Haynes manual states it should be 142.5. Also I...
  18. sly409

    question for you guys with smaller batteries

    Hey fella's, So I'm switching over to a smaller 5ah battery that I plan on relocating it to under the cafe style seat I plan on fabricating later on and I was wondering what you guys did for the battery cables? The connectors for the small battery are .187" quick connect type. Were you guys...
  19. JPaganel

    Threw the chain today

    A few days ago I looked at my chain and thought it looked a little loose. I decided that since I had no idea how old it was I would just get a new one. eBay is full of correct chains for $25 shipped, so the cost wasn't prohibitive. Generic chains are usually long, so I ordered a chain breaker...
  20. S

    thoughts on running synthetic oil

    Wondering if its a good idea to run synthetic oil in my 400 any thoughts??