1. B

    Carburetor Problems BS34 1979 XS400

    The Bike I have came with carbs that are not original and I am having several problems getting them set up. 1. What is the correct level for the float bowl as measured with a clear tube? The original floats sank and have been replaced. 2. The bike runs but is rather anemic. The jets and needle...

    Wanted - 1977 XS360 CARBS NEEDED

    Found, thanks
  3. J

    1981 Yamaha XS400 left cylinder not firing

    Hello I have a 1981 Yamaha xs400 that I bought for 50 dollars and rebuilt. The latest problem is left cylinder does not fire. What I've done so far is switch the spark plugs, and ignition coils that didn't change anything. Then I did a compression test they were both around 150 psi. Finally I...
  4. J

    Is my carb ruined? :/

    Hi dudesters, so im thinking about getting this old bike running, and got around to doing the carbs after a short span of inactivity (the thing has been dismantled for 7 years give or take). So to my surprise i found both idle jets were jammed in too far, subsecuently got stuck and the tips of...
  5. F

    1982 XS400R Seca DOHC Carb Boots

    Hi all, I am restoring an 82 DOHC and have bad intake boots causing a vacuum leak. I'm having trouble finding any that fit, almost everything online is for the SOHC variant. Anyone have a lead on intake boots for the DOHC model?
  6. Ben_Wagner

    Quarantine Project: '81 XS400 Special

    I recently have started working on my uncle's/dad's XS400, my first motorcycle project. I have worked with QT50's and other small mopeds in the past, but nothing this size. The bike hasn't been ridden seriously since the '90s as far as I know, although it has ran a few times since then. Today I...
  7. bricks

    Carb fuel inlet, general question

    Hello everyone. First post, thanks for having me :) A friend gave me a 1983 Yamaha xs400 Maxim (wohoo!) and I just started fixing it up. It cranks but doesn't start/fire, so I rebuild/cleaned the carb, re-installed, set the petcock to prime and let it sit for a few minutes... It still won't...
  8. dannyTheBoat

    Carb intake mod

    Hey all, I have a '82 xs400 that has been mine for about 4 months now. I am a new rider and new to wrenching and I have found a lot of good info on this forum. My bike is below. As you can see, it is a bit chopped up, but the PO did a good job with it and it runs very strong. Lately it has been...
  9. Aedan Graves

    Replacing carbs with non-OEM?

    Hey all, It's been a while since I've posted anything on the forums and I come with a question. The situation; I picked up my bike used Nov of last year, and the previous owner didn't at all take care of the bike, failing to do basic maintenance. As such the carbs needed cleaning or a rebuild...
  10. member14827

    Advice on squeezing carbs into boots

    So, I've got a new set of carb boots on my 80 XS400G. I'm ready to mount a set of stock BS34 carbs which are, obviously, bolted together as one "unit." Any advice on how to finagle the carbs into those boots? It's so tight and I can kinda rotate one in, but never the other, and never both at...
  11. N

    XS400J (Maxim) Alternative Forks

    Hi there, I hope it's ok to post this. I'm very new to the forum. I am in the UK and just bought an xs400j (Maxim). I was hoping someone has found some alternative forks for this bike because being in the UK, It's really hard to get frame & body parts. I'm not adverse to changing the head...
  12. ohnomogan

    78 Rebuild

    Hey, guys. I’m a newbie here. Just looking for some tips on my first rebuild. First up, I’m looking for a carb rebuild kit. I’ve checked a few out on eBay, but I’m not finding many that match my year. Any suggestions on good sellers/etc?
  13. Dav-len

    Wanted - Bs34 carburetors

    Good day all I am urgently looking for a Bs34 carburetor for my xs400 special I think it's 1980-81 She is currently standing stripped down,and waiting on me to find a new carburetor on witch I can not find .please let me know if anyone has anything.
  14. Lego

    Wanted - brass carb float - europe?

    brass float for xs400 sohc needed. somebody from europe willing to sell ? thx
  15. heritage

    Tuning XS400 82 Heritage Special

    Hello and thanks to everyone for the help in the past helping me out. I have a question once again I believe I have a good handle how to clean and how to ensure there are no air leaks at the carb. But I am not sure where to go when a bike starts great, idles well, choke will responded , throttle...
  16. frankyaxs400

    mikuni idle screw?

    hey everyone ive been having a hard time locating anything on my mikuni carb for my 1984 xs400 seca. our goal is to tune it when we get it on the bike im looking for the idle screw but cant seem to locate it, and ive created this account to get help with it. but anything will help...
  17. SpiderWrench

    Carburetor nightmare; wasps+ wrong broken mixture screws on top broken mixture screws…

    The 81 XS400 has been parked since late August when I rode it to its new home and parked it in my basement. It has never run particularly well, and has always had idle problems according to PO because it had to be tuned to the 2-1 exhaust. When I went to remove the carbs, I thought they looked a...
  18. N

    Throttle Shaft Seal Replacement

    My 1977 xs400 needs throttle shaft seals to be replaced. Does that mean it needs a full carb rebuild? The previous owner said he "rebuilt the carb not too long ago." I'm guessing he either overlooked throttle shaft seals or used bad ones. What do y'all think?
  19. Brazzz

    For Sale - 1981 XS400 Special Part Out

    Will ship any part just send me a zip code and I can get a quote. Bike was running when the motor was pulled, all parts should be in working order. What is pictured is what parts I have, the only things not in the photo are the exhaust and carburetor. Name a reasonable price for the part you'd...
  20. Winnipeg_79_XS400

    1979 XS400F SOHC

    It's about time I post a thread for my bike. I bought my first bike and am "so far" managing to figure out how to get things done, mostly from this site, Thank you. That said, I am having my carbs cleaned, I'm trying to figure out how to tune them for my bike when I get them back. I have read 3...