carburetor jetting

  1. Signal

    Question regarding Mikuni Hex shaped jets as used in VM 34’s and 36’s.

    Regarding the numbering and the jet size. From what I have read the number is related to the amount of water flow through the orifice over a given time and not the size of the orifice. Is it correct to assume that a #360 will flow twice the amount of a #180 jet if all other things are equal?
  2. MadMax1996

    Makuni VM34 Carbs = Backfire / Throttle Hang

    Yesterday I had swapped my failing BS38 carbs for brand new pre-jetted Makuni VM34 roundslide carbs. The fuel is now running through 2 fuel lines - each going tank to carb separately with shutoff valves and fuel filters in between. It seems to be running well enough to head down the road...
  3. SRosso

    Carburetor Jetting Need Help

    Hello, I have a 1980 XS650 that is stock except for UNI pod filters. I am having trouble with the jetting on the bike it has stock carburetors as well. The previous owner changed the main jet to a 140 when he did the filters. At first, it ran well then it developed a surge taking off from a stop...
  4. Gavin Mackenzie

    First bike 81 xs650 bobber. Flat power at high rpm

    Hey there everyone, new here, new to riding, working on bikes etc... looking for a little advice in the right direction. Recently purchased my first road bike 81' xs650 bobber. Fun little bike so far! Issue I'm running into is, the the bike starts fine, idles fine, and rides fine, as long as I...
  5. DirtyErnie

    Read My Plugs

    After missing the last two summers, I finally got the bike rolling today. I've changed to Ninja 500 carbs and a stock 2-2 exhaust. What do you see in my plugs? I see: 1. The vacuum leak at idle, inner throttle shaft seals are out. 2. Too much timing. 3. Wrong heat range? These are the stock...
  6. M

    Is a 150 main to big?

    Is a 150 main causing my midrange break-up? I am running a bs38 on my 1978 xs650. I have pod filters and open exhaust. From every post I found I should run a 150 main and 32.5 pilots. I've done all the tuning from the tensioner, valves, timing etc... Synced them with a manometer, adjusted...
  7. bandit78

    Jetting?? Headder Only, Homemade Intake Filter

    I read up on jetting for dif mods but noting seems to be clear cut for my set-up. Why not ask the community? I currently have stock jet settings and seem to run super rich. I foul plugs regularly.:banghead: Points, timing/time chain all have been set/adjusted properly. Running headder...
  8. J

    pilot jet issues on xs650 bs34 carbs

    I am rebuilding the carbs on my 80 Xs650. All the research that I have done tells me that I have bs34 carbs. I tear them apart pull all the jets and what not clean everything well , decide to go with the dyno jet kit from mikes xs. It comes and I find that the pilot jets that came with kit are...
  9. Socopunk

    So Close! Carb problem????

    Here's the LowDown: '73 TX650-K&N airpods, stock headers, Shorty Mufflers. Main Jet 135, Pilots stock, Needle at 1 slot below middle. Mixture screw 1 turn out from seated. Everything else is stock. Here's the Problem: Bike starts on 1 or 2 kicks with choke on. Flip off the choke and...