1. M

    Help with 78 special bs38 carbs please advise needed.

    Some background on the bike, it’s all stock and I recently rebuilt the carbs and synced using a digisync. Bike seems to make a “puffing” noise and die while pulling to a stop sign at near full stop. Bike will be impossible to start for awhile until I let it sit for after that. I did not set the...
  2. E

    Quick carb verification, please.

    So just to ask because I don’t know and while I can read, I wanna be sure before I order stuff.. short background, got the bike in a box and there are parts here and there from a couple different bikes. I am sure the one on the left (or top, picture depending) is a 34 and the one under it is a...
  3. X

    BS38 Throttle Cutaway

    Hey everyone, I’m running over the carbs on my 79 special. I’ve got everything up to spec, but I am interested in how to determine my throttle cutaway. I know what cutaway is but in my manual, the spec for my cutaway is listed as #120. Can anyone tell me what this means?? cheers!
  4. anthony44

    1976 bs38 pilot screw

    From what i heard, the 1976-77 bs38's dont have an o-ring and little washer against that sping on the pilot? Im having a problem where the bike hesitates and breaks up down low when its accelerating. I noticed the pilots looks like they had a tiny bit of gas around them as i was trying to adjust...
  5. Kubes42

    Carb questions from another new guy! - New (to me) 78 cs650

    Hey there, another new guy with more carb questions for those of you who aren't sick of them yet! Heres the story. -History Purchased a 78 xs650 with about 9000 miles that was kept just outside of the D.C. area, and brought it down to Mississippi. Bike is super clean, new gaskets just about...
  6. V

    Help! My carbys are a mash up - what to do?

    Hi guys, So I have a 74tx650a , that is running (never tested out how well) and hasnt been registered for a while (I know it was registered by the 3rd owner before me). So I thought I would give the carbys a birthday (float gaskets were leaking). So far they havent been too bad but as its got...
  7. zoomoto

    Bs38 mystery hanging idle with 35 pilot

    hey guys. Thanks for all the help previously. it goes. You fix one problem only to discover more. Here’s my current set up. •Pamco with e-advance •PMA/Capacitor •uni pods •pandemonium ya mommas (planing on modifying them for mufflers) •78-79 bs38s with matching internals •jbm...
  8. 79josh81

    Mikesxs BS38 Pilot Mix Screw O-Rings

    So I just got some new pilot screws for my 79’ with BS38 carbs. Mikesxs has a disclaimer about the o-rings on the replacement mix screws not fitting in all carbs potentially. Of course I’m one of the sorry sons of a bitch that the o-rings ended up being to big for my carb body. I would just pull...
  9. 79josh81

    BS38 Tuning Issue

    So I decided to re-tune and sync the carbs on my 79’ today because, since I finished this build and initially tuned and synced the carbs, the left cylinder seems to run smooth and the right cylinder just seems to not be running as smooth. It runs, but just not with the same steady cadence as the...
  10. Robert Dell Aquila

    Vacuum leak

    Hi everyone, hope all is well. So I have been working on my 78' through the winter so I can ride for spring, shes almost there I can feel it. However, I noticed something strange. The LH cylinder is running a lot hotter than the RH. When I spray the RH with carb clean the rpms shoot up. And when...
  11. BeetsnGreens

    Carburetor ID

    Hello all. I have a set of carbs that are not original to this bike. I have a 1980 XS650SG. The carbs are BS38's, either the 76-77 model or the 78-79 model. I can't figure out the difference between those two, so help would be greatly appreciated. I may order a rebuild kit, but need to know...
  12. GeorgeOC

    Sold / Found / Inactive - SOLD - Mikuni BS38 Carburetors $150

    For sale, a set of good condition BS38 carbs. Photos below. Shipping is from 92675. Thanks!
  13. S

    Wanted - XS1B BS38 carburetor bowl

    Hi; Just run in some bad luck, pilot screw is so seized, i'm unable to take it out. Now it has a screw extractor broken inside. I think it has no salvation. So I'm looking for a carburetor bowl, for my XS1B, late model; It's like the one in this thread ...
  14. Little J

    For Sale - BS38 carbs, UNI filters, reg/rec

    Make me an offer on this set of Mikuni bs38’s! I have just cleaned them pretty well and have an uninstalled rebuild kit (new gaskets, needles, jets) but have decided to go the vm34 route. Carbs run great and the UNI filters were mounted for less than 100 miles on a 79 SF (one small cut inside...
  15. cmarts

    1974 TX650 New Owner Help/Tips

    Hi I am a new bike owner and I recently purchased a 1975 yamaha xs650 (TX650B?). Heres what I know about the bike. It was originally purchased from a farm in Southern Saskatchewan where it had been stored in a barn for a long time. The previous owner lost interest in the bike and let it sit...
  16. eight0

    Finally finished my XS2

    Well, I have finally finished my XS2.. (I say that but are we ever finished). I've fitted indicators and mirrors since taking these pictures as riding in London whilst holding your arms out isn't fun. the last picture what it looked like when I got it. .
  17. TwoManyXS1Bs

    CruzinImage BS38 carburetor floats -- Review

    This is a follow-up to xjwmx's review thread: CruzinImage offers BS38 float pairs for 1970-1979 carbs. Even though there's different listings for various year groups, they're all the same float set...
  18. ChopperRobb

    77'BS38's with push in main nozzle??

    Hey, it's been a really long time since ive been here but... anywho, ive been reading all the carb literature and whatnot and still need some questions answered, if anyone can... I have a set of early 1977 BS38's...i am of the understanding that they had the screw in main nozzle (that the needle...
  19. F

    Wanted - BS38 Carbs

    just opened mine up on a restoration project and one side has the float posts busted off, the other side has the brass float totally rotted away, and both have severely damaged brass stuck in them. Thinking they're basically not worth saving if I can find usable bodies. I have rebuild kits...
  20. moebius

    Narrowing down air leak 1978 BS38s

    Hey guys, pretty new to the forum and new to working on bikes but I was wondering if I could get some help narrowing down an air leak. I have a 1978 xs650, started riding it this summer and I've had some backfiring popping issues for awhile now, only on the left side. I checked the points then...