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    carb settings

    I recently did a clean and rebuild. Of course it's not running right. I also installed K&N pods. I need to know the intial settings for:

    pilot fuel screws(bottom of carb, the cutout at bowl)
    Air screws ( i think this is 1 1/4 turns out)
    How many inches of mercury should I start with on the #3 carb?

    Thanks in advance to anyone that can help,
    Chris

    #2
    oops bike is a '78 750E

    Comment


      #3
      If the bike will run well enough to do a 1/3 throttle position test, I suggest doing that and get plug reads after chopping off. Be sure the bike is completely warmed up first. Bench synch before this test.
      I suggest this because if you get lean reads, the jet needles will have to be raised for those pods. Any changes to the VM carb jet needles requires a new bench and vacuum synch. If your jet needle e-clips are still in the factory (3rd) position, you'll be lean for sure. Then you need to get the main and pilot circuits right too, but changing those doesn't require re-synching.
      As for your screw settings, try 1 1/2 turns out from LIGHTLY seated on the pilot fuel screws (underneath). Then set the side air screws to 1 3/4 turns out as a starting point. The side air screws are adjusted using the highest rpm method with an idle set at 1,000/1,100 rpm's.
      Fine tuning the pilot fuel screws will almost certainly be needed. They are sensitive to adjustments. With K&N's only, they generally end up somewhere between 1 1/4 and 1 1/2.
      I don't worry about the initial vacuum levels I see at start up. If you did the bench synch correctly and have no mechanical problems, the levels you see will be fine, though pulsing at idle. I adjust the levels at a higher rpm than some. I set them around 3,000/3,500 rpm's. The bike will heat up fast at these rpm's so do it quickly. Use two large fans. Be sure the air screws are set (highest rpm method) and the ignition timing/advance set before the vacuum synch. The valve clearances should be set between .03 and .08mm too.
      And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
      Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

      Comment


        #4
        Also, don't over-tighten the throttle valve screw adjuster holding nuts. 3.5 ft/lb is the factory torque. If you are more comfortable setting the vacuums at say... 2,000/2,500 rpms, then do so. I set them at something closer to a typical cruising speed but if you have little experience vacuum synching, you can over-heat the bike setting at higher rpm's. Even 2,000 rpm's is better than setting them at factory idle.
        And with those K&N pods, REMOVE the two floatbowl vent lines and leave the ports open to breath. Fuel starvation WILL result if you leave the vent lines on with pods.
        And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
        Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

        Comment

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