1. BambinoFan

    Carb cleaning party!

    Haha! New owner of a 84 maxim. Looking to work my carbs for the first time this fall, wondering if anyone else wants to work on thiers together?
  2. 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...
  3. jvdavidson

    Carbs or Coils...or something else???

    Hello everyone, haven't been here in a while because I haven't really putzed around with my XS400 for a few years. I've got a '78 XS400-2E that I had running exquisitely back in 2016 until I started having electrical issues - basically the original mechanical voltage regulator was fighting me...
  4. K

    Restoration project|1982 XS400SJ HERITAGE w/Bobber frame

    This is my first bike guys and I’m really excited to start getting things working. I’m planning on taking my time and doing a restoration with it over the winter. Bought it from previous owner who let it sit with it on, and gas in the tanks. It won’t start and im pretty sure I just need to...
  5. D


    Hi all, not sure what to do about this one. Just took my 82 out and took it on the highway for the first time going between 50-75 for about 10 minutes. Once I come back into town, at every stop it wants to die and frequently sounds like the left cylinder is cutting out. Furthermore while riding...
  6. J

    Carb tuning advice

    Hi, need some advice for getting my bike running right. It’s an xs400se The main issue right now is the rev hang it has on idle. And occasionally won’t idle will just stall, or when idling and going to throttle it cuts out. On warmer days it will idle but have rev hang. Guessing it’s running...
  7. J

    '79 bouncing idle. I'VE TRIED EVERYTHING (kinda)

    So this has been a year and a half worth of trying to figure out what is wrong with my bike. I bought this fully running about 3 years ago I think, and rode it around with no problems for about a year and a half. Here's my problem now: My idle will bounce around a bit and "searches." After...
  8. HicklingSam

    BS34 - 79, or later?

    Hello everyone. First post! I've done a bit of searching, but have a couple of questions about some carbs I've just bought - as I have a bit of time to wait for them to arrive, and was hoping to get some other bits ordered whilst waiting. I've got a '79 250 frame, which I'm putting a '81 (14V...
  9. Houseman39

    Starting Reassembled Engine

    Thanks to all who helped me on my previous thread! (Reassembling the engine - check it out here Now that I've got the new crankshaft and rods in and the whole engine reassembled I'm trying to breathe life back into my 1980 XS400...
  10. C

    Xs400s 1980 carbs help

    So first things first. I'm new to carburetors. I pulled the float bowls they're clean, but when I throttle to start the bike the floats, I think, they don't open with the butterfly valve. I can push them into the float bowl and they drop down at about the same speed more or less. Do they need...
  11. SoraXS400

    Carbs Leaking Like Crazy

    It's the luck of working. A few weeks ago I took off all the panels to be spray painted, never touched the carbs (in fact I drained them) and now when everything is put together, the carbs are leaking out of every orifice. Not sure what to do, my petcock was also leaking no matter what, even...
  12. killjoy33

    Im missing Pilot Jet plugs

    Hello I have a 1981 xs400h. I recently rebuilt the carbs(mikuni bs34 cv) but i noticed i do not have any pilot jet plugs. The reason i rebuild the carbs was because the left carb was leaking gas to the left air filter. Do i need to buy pilot jet plugs? The right carb never leaked any gas...
  13. axl_foley

    new issue: idles perfectly but on throttle, pops loudly and fires unevenly

    hey! these forums have helped me do so much work on this bike over the past year or two and i had it running beautifully. but i recently moved to CA and brought the bike in the back of a moving truck. there was atleast one giant bump i hit where i thought everything in the back of the truck...
  14. S

    1978 XS400 Problems

    Hello all, and may I thank you for supporting such a wonderful and helpful site. Two weeks ago I bought a 1978 XS400 (2LO VIN) for $50. It had been sitting for 3 years, but had run when it was parked in a shed, or so the PO said. I brought it home and me and a friend sprayed some starting...
  15. Monowakari

    Idle Hesitation/Bog - '78 xs400

    Tore my carbs apart and cleaned them thoroughly with carb cleaner. Set the timing to be fairly accurate and point gap is perfect. Valve clearances all within spec on the tighter side (quite quiet now, might have read my old posts on the valve train noise, has all but gone away now with valves in...
  16. Monowakari

    Clatter/Noise And Compression

    Hey, Changed my oil and adjusted valve clearances yesterday, now valves all within spec. Took a video before right cylinder intake valve was set properly. Didnt like the sound so went back over and checked all clearances. I just did a poor job on one of them (was .003 out! on an intake valve...
  17. O

    For Sale - 1982 Yamaha XS400 Carburetors OEM 1977-1983

    Off of a 1982 Yamaha XS400 Mikuni in good used condition. Everything moves freely and have been well cleaned. Asking $150 w/free shipping. Make payments via PayPal, Chase Quick Pay, or Venmo. US ONLY! Sorry!
  18. C

    BIKE NOT STARTING... Help! (Throttle and choke kill electric start)

    Hey guys, so after getting my bike back from the shop two weeks ago, where it left running, it has decided not to start. When I attempt to start the bike with my electric start, if I have the clutch out or if I give the bike throttle, my electric starter hits a dead spot and sounds like it's...
  19. T

    How to remove carbs on 1982 XS400 Maxim

    Need to remove carbs to clean them out, no fuel getting to RH carb. Do I need to remove the air box to get the carbs out. If so how do I get the air box out. Thanks, TonyB
  20. U

    What size screws for carbs?

    Hi I am going to need to take apart my carbs again and I promised myself that if I did I would replace all the screws (some are stripped) on the body of the carb with stainless steel socket head (Allen) screws does anyone know what sizes and how many of each to redo a set of 1980 xs400g bs34s? I...