Carb info request

cosack54 · Posted: June 8, 2009, 8:06 am Post subject: Carb info request

Hey everybody! New to the site with a 1981 xs650sh. Recieved this bike on a swap. Have slowly been fixing her up and she still has some minor flaws but is starting to shape up nicely. I've added 2 into 1 pipes and I know that this magnifies the lean conditions that already exist. Recently purchased a jet kit from Mikes XS. Instructions that came with the kit stated that I should use a 135 main jet and a 45 idle jet, mixture jet out 2.5 full turns and needle clips in the #3 position. At the same time in his "Tech Tips" section it states 142.5-147.5 mj, #45 pj, 127.5 air jet, mix out at 2.5-3 turns , fuel level shut off at float bowl set high. Can someone straighten this out for me?
I would greatly appreciate the decipher here!
cosack54

yamalama · Full Member Joined: Nov 14, 2008 Posts: 26

cosack54, This is what I run in my BS34's with good results. 137.5 main jet, which is two sizes up from stock. 42.5 pilot jet, which is the stock size. 135 air jet which is stock. 3 1/2 turns out on the mixture screw. float level at recomended height. I have K&N filters with moderatly free flowing exhaust.

cosack54 · Posted: June 8, 2009, 4:36 pm Post subject: Re: Carb info request

Hello Yamalama! Thanks for the info so far. Answer me this! I'm new to messing around with carbs but I'm trying to learn. What the heck and where the heck is the air jet? I purchased a dyno tune kit from Mikes XS(is this good or bad? I don't know!). The instructions never mentioned anything about an air jet, let alone fuel float adjustments. Can't find any on Mikes XS, unless I'm totally blind.(which I have intermittent bouts of).
Can you or any body else educate me on this! THANKS!

schtipp · Posted: July 15, 2009, 11:26 am Post subject: Re: Carb info request

hey cosack, if your looking into the carb from the air filter side, you'll see four little holes around the perimeter and an oval one up top. the air jet is in the one little hole. to set the float level you have to remove the bowls and turn the carbs upside down. let the float come to rest on the float valve and measure from the casting to the high part of the float. manuals differ as does experience, but 26mm is ballpark starting point. do a forum search for floats and you will come across a good diagram.i would get a manual though.

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