Ad Widget



No announcement yet.

Pre 750 float heights

  • Filter
  • Time
  • Show
Clear All
new posts

  • Pre 750 float heights

    after a couple trouble free seasons after rebuilding the carbs, my bike has been acting up.After the rebuild I think I had my float heights off a bit. I went level with the carb bottoms at easy set tilt. Stumbled a little off idle but smoothed right out. Pretty erratic idle too Not enough to tear the bike down again. I ran it like that all season. Now Iím here,Starts right up with choke, warms up, after a few minutes I can take choke off. Runs for five minutes and dies. Wonít start back up for a couple hours. Iím thinking not enough fuel, maybe my floats were too high at 15 mm. I watched the carbs 102 video and set my float heights to 13mm. Ran for a few minutes with a hanging gas bottle switching back and forth to each fuel line and with vac line plugged off seemed to be smoking more(rich ?) gas seemed to be going down fast so I took a quick look at the oil sight glass and it looked like gas in the oil. (Floats too low?)
    One more detail, I found that one of the vac caps on the #3 carb was missing. May explain erratic idle.
    thanks in advance. Any suggestions will be appreciated

  • #2
    Btw. I have read and reread carbs 101 and nothing is jumping out at me.


    • #3
      Just a couple of thoughts from reading your post. 1)The missing vac cap will definitely have an effect on your idle since it allows a vacuum leak. Should cause a high idle. 2) Carbs 102 is for post Kats not pre's. I know they are similar but be aware that they are different carburetors with different settings. 3) If you were looking at the oil sight glass while it was running, it will look odd for sure. The best way to check it is to pull the dipstick and smell the oil. If it smells like gasoline, then you are getting too much fuel and it's getting past the rings into the oil. Time for an oil change. 4) Is the port that is normally hooked up to the back of the petcock plugged off? If not, that is another leak.


      COURAGE -

      Freedom is the sure possession of those alone
      who have the courage to defend it.

      First Sergeant(Ret) - US Army - 21 years


      • #4
        All lines were properly hooked to petcock. 2 fuel feeds, a vac line a vent to both petcock and tank as well as the fuel level wires. I think my main concern was dying after warm up. I was thinking starving for fuel. I think my floats are too high now for sure.


        • #5
          Set mine to 14.5mm and were fine
          ďAnything that happens, happens. Anything that, in happening, causes something else to happen, causes something else to happen.
          Anything that, in happening, causes itself to happen again, happens again. It doesnít necessarily do it in chronological order, though.Ē
          ― Douglas Adams


          • #6
            Iíll give that a try. Thank you